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Combination of Model-based Observer and Support Vector Machines for Fault Detection of Wind Turbines

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International Journal of Automation and computing 2014年第3期11卷 274-287页

作者： Nassim Laouti Sami othman Mazen Alamir Nida Sheibat-othman Université de Lyon Université Lyon 1 CNRS CPE Lyon UMR 5007 LAGEP F-69616 Villeurbanne France Gipsa-lab/CNRS University of Grenoble Rue de la Houille Blanche 38400 Saint Martin d Heres France

Support vector machines and a Kalman-like observer are used for fault detection and isolation in a variable speed horizontalaxis wind turbine composed of three blades and a full converter. The support vector approach is data-based and is therefore robust to process knowledge. It is based on structural risk minimization which enhances generalization even with small training data set and it allows for process nonlinearity by using flexible kernels. In this work, a radial basis function is used as the kernel. Different parts of the process are investigated including actuators and sensors faults. With duplicated sensors, sensor faults in blade pitch positions,generator and rotor speeds can be detected. Faults of type stuck measurements can be detected in 2 sampling periods. The detection time of offset/scaled measurements depends on the severity of the fault and on the process dynamics when the fault occurs. The converter torque actuator fault can be detected within 2 sampling periods. Faults in the actuators of the pitch systems represents a higher difficulty for fault detection which is due to the fact that such faults only affect the transitory state(which is very fast) but not the final stationary state. Therefore, two methods are considered and compared for fault detection and isolation of this fault: support vector machines and a Kalman-like observer. Advantages and disadvantages of each method are discussed. On one hand, support vector machines training of transitory states would require a big amount of data in different situations, but the fault detection and isolation results are robust to variations in the input/operating point. On the other hand, the observer is model-based, and therefore does not require training, and it allows identification of the fault level, which is interesting for fault reconfiguration. But the observability of the system is ensured under specific conditions, related to the dynamics of the inputs and outputs. The whole fault detection

关键词： Fault detection and isolation wind turbine Kalman-like observer support vector machines data-based classification

Endothelial progenitor cells, potential biomarkers for diagnosis and prognosis of ischemic stroke: protocol for an observational case-control study

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Neural Regeneration Research 2020年第7期15卷 1300-1307页

作者： Kamini Rakkar othman othman Nikola Sprigg Philip Bath Ulvi Bayraktutan Stroke Division of Clinical Neuroscience University of Nottingham Clinical Sciences Building City Hospital

Ischemic stroke is a devastating,life altering event which can severely reduce patient quality of *** years of research there have been minimal therapeutic *** progenitor cells(EPCs),stem cells involved in both vasculogenesis and angiogenesis,may be a potential therapeutic *** a stroke,EPCs migrate to the site of ischemic injury to repair cerebrovascular damage,and their numbers and functional capacity may determine patients'*** study aims to determine whether the number of circulating EPCs and their functional aspects may be used as biomarkers to identify the type(cortical or lacunar)and/or severity of ischemic *** study will also investigate if there are any differences in these characteristics between healthy volunteers over and under 65 years of age.100 stroke patients(50 lacunar and 50 cortical strokes)will be recruited in this prospective,observational case-controlled *** samples will be taken from stroke patients at baseline(within 48 hours of stroke)and days 7,30 *** will be counted with flow *** plasma levels of pro-and anti-angiogenic factors and inflammatory cytokines will also be *** endothelial cells will be cultured to be used in tube formation,migration and proliferation functional *** outcome is disability or dependence on day 90 after stroke,assessed by the modified Rankin *** outcomes are changes in circulating EPC numbers and/or functional capacity between patient and healthy volunteers,between patient subgroups and between elderly and young healthy *** started in February 2017,167 participants have been *** will end in November *** Midlands-Coventry&Warwickshire Research Ethics Committee approved this study(REC number:16/WM/0304)on September8,*** version:*** Bayraktutan Dunhill Medical Trust EPC Study was registered in ***(NCT02980354)on November 15,*** st

关键词： ageing biomarkers cortical stroke endothelial progenitor cells ischemic stroke lacunar stroke observational study stem cells

The effect of natural products combination on MCF-7 cells exceeds tamoxifen therapeutic dose effects in vitro

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BIOCELL 2023年第4期47卷 891-904页

作者： ZEINAB KLAAB AZIZA HASSAN JAWAHER ALBAQAMI faizah A.ALMALKI Department of Biology Taif UniversityTaif21944Saudi Arabia Department of Biotechnology Taif UniversityTaif21944Saudi Arabia

Cancer remains to be one of the most severe sicknesses *** have kept rising over the *** cancer(BC),which is among the leading types of cancers and predominantly affects women,is the second leading cause of cancer *** have developed interventions over the years;however,the BC survival rate has not improved since the *** has created the need for novel drug interventions that would manage and treat BC more *** study focused on using a combination of natural product extracts such as phytoestrogen(Ziziphus jujube)and Tannin nanoparticles(NP99)together,which we have referred to as(***99)and tamoxifen(Tam)as one of the leading BC drugs since the 70s,in treating *** effectiveness of Tam if used alone in the treatment and if combined with ***99 was evaluated using MCF-7 cells in *** findings showed that the combination treatment of ***99 affected the proliferation and viability of MCF-7 cells more than Tam at a 10μg/mL ***,***99 with Tam stimulated the maximum reduction of MCF-7 proliferation and viability in a time-dependent ***,Tam and ***99 augmented the DNA fragmentation percentage combined with the upregulation of the apoptotic ***,the results showed that the apoptotic impact of ***99 and Tam on MCF-7 cells may be intermediated by down-regulating some genes such as Claudin-1 followed by down-regulating mRNA expression of MMP-9,VEGF,and BCL-2 genes of treated *** Tam with ***99 considerably enhanced the effectiveness of conventional *** a result,this study suggested that the ***99 was ideal for developing effective natural treatments that would improve BC outcomes.

关键词： Breast cancer DNA fragmentation Apoptosis

Electro-optical properties and(E,F) phase diagram of fluorinated chiral smectic liquid crystals

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Chinese Physics B 2018年第10期27卷 570-577页

作者： R Zgueb H Dhaouadi T othman Universite Tunis El-Manar Faculte des Sciences de Tunis Laboratoire de physique de la matiere molle et de modelisation electromagnetique (LP3ME) Campus Universitaire Farhat Hached 2092 Tunis Tunisie

Fluorinated smectic liquid crystals each with a biphenyl benzoate rigid core are investigated. Molecular structures of the studied compounds have difference only in fluorine position and the length of the carbon chain. Dielectric relaxation study and electro-optical measurements are carried out with the classical SSFLC geometry. The field-induced phase transitions are studied and the（E,T） phase diagram is established.

关键词： smectic liquid crystal dielectric relaxation electro-optical properties phase transition (E,T)phase diagram

Outgrowth endothelial cells form a functional cerebral barrier and restore its integrity after damage

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Neural Regeneration Research 2020年第6期15卷 1071-1078页

作者： Rais Reskiawan Abdulkadir Mansour Alwjwaj othman Ahmad othman Kamini Rakkar Ulvi Bayraktutan Stroke Division of Clinical Neuroscience Clinical Sciences Building School of MedicineHucknall Road Nottingham NG5 1PB UK

Breakdown of blood-brain barrier,formed mainly by brain microvascular endothelial cells(BMECs),represents the major cause of mortality during early phases of ischemic ***,discovery of novel agents that can effectively replace dead or dying endothelial cells to restore blood-brain barrier integrity is of paramount importance in stroke *** endothelial progenitor cells(EPCs)represent one such agents,their rarity in peripheral blood severely limits their adequate isolation and therapeutic use for acute ischemic stroke which necessitate their ex vivo expansion and generate early EPCs and outgrowth endothelial cells(OECs)as a *** analyses of these cells,in the present study,demonstrated that only OECs endocytosed DiI-labelled acetylated low-density lipoprotein and formed tubules on matrigel,prominent endothelial cell and angiogenesis markers,*** analyses by flow cytometry demonstrated that OECs expressed specific markers for sternness(CD34),immaturity(CD133)and endothelial cells(CD31)but not for hematopoietic cells(CD45).Like BMECs,OECs established an equally tight in vitro model of human BBB with astrocytes and pericytes,suggesting their capacity to form tight *** injury mimicked by concurrent deprivation of oxygen and glucose(4 hours)or deprivation of oxygen and glucose followed by reperfusion(20 hours)affected both barrier integrity and function in a similar fashion as evidenced by decreases in transendothelial electrical resistance and increases in paracellular flux,*** scratch assays comparing the vasculoreparative capacity of cells revealed that,compared to BMECs,OECs possessed a greater proliferative and directional migratory *** a triple culture model of BBB established with astrocytes,pericytes and BMEC,exogenous addition of OECs effectively repaired the damage induced on endothelial layer in serum-free *** together,these data demonstrate that OECs may effect

关键词： cell-based therapy endothelial progenitor cells endothelium ischemic stroke neurodegeneration novel therapeutics outgrowth endothelial cells regenerative medicine stem cells translational medicine

The effect of rotation on plane waves in generalized thermo-microstretch elastic solid with one relaxation time for a mode-I crack problem

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Chinese Physics B 2011年第7期20卷 266-278页

作者： Kh.Lotfy Mohamed I.A.othman Department of Mathematics Faculty of ScienceZagazig UniversityP.O.Box 44519ZagazigEgypt Department of Mathematics Faculty of SciencealmithnabQassim UniversityP.O.Box 6666AlmithnabKingdom of Saudi Arabia

The present paper is aimed at studying the effect of rotation on the general model of the equations of the generalized thermo-microstretch for a homogeneous isotropic elastic half-space solid, whose surface is subjected to a Mode-I crack problem. The problem is studied in the context of the generalized thermoelasticity Lord Shulman＇s （L-S） theory with one relaxation time, as well as with the classical dynamical coupled theory （CD）. The normal mode analysis is used to obtain the exact expressions for the displacement components, the force stresses, the temperature, the couple stresses and the microstress distribution. The variations of the considered variables through the horizontal distance are illustrated graphically. Comparisons of the results are made between the two theories with and without the rotation and the microstretch constants.

关键词： Lord-Shulman's theory thermoelasticity microrotation microstretch

Generalized thermoelasticity of the thermal shock problem in an isotropic hollow cylinder and temperature dependent elastic moduli

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Chinese Physics B 2012年第1期21卷 289-294页

作者： Ibrahim A.Abbas Mohamed I.A.othman Department of Mathematics Faculty of Science and Arts-KhulaisKing AbdulAziz UniversityJeddahSaudi Arabia Department of Mathematics Faculty of ScienceSohag UniversitySohagEgypt Department of Mathematics Faculty of ScienceZagazig UniversityP.O.Box 44519ZagazigEgypt

In this paper, we construct the equations of generalized thermoelasicity for a non-homogeneous isotropic hollow cylider with a variable modulus of elasticity and thermal conductivity based on the Lord and Shulman theory. The problem has been solved numerically using the finite element method. Numerical results for the displacement, the temperature, the radial stress, and the hoop stress distributions are illustrated graphically. Comparisons are made between the results predicted by the coupled theory and by the theory of generalized thermoelasticity with one relaxation time in the cases of temperature dependent and independent modulus of elasticity.

关键词： generalized thermoelsticity thermal shock temperature dependent elastic moduli finiteelement method

Single-valued neutrosophic relations and their application to factors affecting oil prices

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CAAI Transactions on Intelligence Technology 2020年第2期5卷 115-120页

作者： Yenling Chaw Lazim Abdullah Mahmod othman Department of Mathematics Faculty of Ocean Engineering Technology and InformaticsUniversiti Malaysia TerengganuKuala Nerus 21030Malaysia Fundamental and Applied Science Department Universiti Teknologi PETRONASPerak 32610Malaysia

The recent boom of economic activities has escalated the demand for oil that eventually will affect its ***,oil prices are difficult to predict because most of the factors affecting oil prices are vague and *** challenges in predicting oil prices urgently require a novel approach where issues related to multiple-factors,uncertainty,and periodicity can be *** authors propose the single-valued neutrosophic relations based decision-making method inspired by the three memberships of neutrosophic sets,and amplitude and periodicity of complex *** proposed method is applied to the case of oil prices where six factors affecting oil prices and six benchmarks measuring oil prices are *** new method combines with complex neutrosophic numbers and algebraic relations,and can suggest the most influential factor that affects oil *** the periodicity of 24 months,computation results verify the‘global economic rate’as the most influential factor that affects the prices of *** main contribution of this study is the development of a neutrosophic relations-based decision-making method to suggest the most influential factor that affects oil *** result provides evidence on the feasibility of the proposed method in suggesting the influential factors that affect oil prices.

关键词： valued prices eventually

Existence and numerical approximation of a solution to frictional contact problem for electro-elastic materials

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Applied Mathematics(A Journal of Chinese Universities) 2024年第2期39卷 201-219页

作者： othman Baiz EL-Hassan Benkhira Rachid Fakhar University Ibn Zohr Lab.ESERFP of OuarzazateMorocco University Moulay Ismail Faculty of SciencesLaboratory MACSESTMBP 3103Toulal-MeknesMorocco University Sultan Moulay Slimane Laboratory LS2MEPolydisciplary Faculty of Khouribga25000 KhouribgaMorocco

In this paper,a frictional contact problem between an electro-elastic body and an electrically conductive foundation is *** contact is modeled by normal compliance with finite penetration and a version of Coulomb’s law of dry friction in which the coefficient of friction depends on the *** addition,the effects of the electrical conductivity of the foundation are taken into *** model leads to a coupled system of the quasi-variational inequality of the elliptic type for the displacement and the nonlinear variational equation for the electric *** existence of a weak solution is proved by using an abstract result for elliptic variational inequalities and a fixed point ***,a finite element approximation of the problem is *** some regularity conditions,an optimal order error estimate of the approximate solution is ***,a successive iteration technique is used to solve the problem numerically and a convergence result is established.

关键词： piezoelectric material frictional contact variational Inequality fixed point process finite element method error estimation iteration method