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Design an Artificial Neural Network by MLP Method;Analysis of the Relationship between Demographic Variables, Resilience, COVID-19 and Burnout

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International Journal of Mental Health Promotion 2022年第6期24卷 825-841页

作者： Chao-Hsi Huang Tsung-Shun Hsieh Hsiao-Ting Chien ehsan eftekhari-Zadeh Saba Amiri Office of Research and Development Tunghai UniversityTaichung407224TaiwanChina Nanyang Institute of Management The Central 059817Singapore Krirk University Thanon Ram IntraKhwaeng AnusawariKhet Bang KhenKrung Thep Maha Nakhon10220Thailand National Taiwan Normal University Graduate Institute of Information and Computer EducationTaipei10610TaiwanChina Institute of Optics and Quantum Electronics Friedrich Schiller University JenaJena07743Germany Managamenet and Entrepreneurship Department Razi UniversityKermanshah67146Iran

In addition to the effect that the COVID-19 pandemic has had on the physical and mental health of individuals,it has also led to a change in the mental and emotional state of many *** among businesses and private companies,which faced many restrictions due to the special conditions of the ***,the present study aimed to design an artificial neural network with MLP technique to analyze the relationship between demographic variables,resilience,COVID-19 and burnout in start-ups in *** research method was *** and employees of start-ups formed the statistical population of the study,based on the statistical sample size of the unlimited community,384 of them were *** data gathering,standard questionnaires include of MBI-GS and BRCS and researcher-made questionnaire of stress caused by COVID-19 were *** validity of the questionnaires was confirmed by a panel of experts and their reliability was confirmed by Cronbach’s alpha *** number of neurons in the input layer was equal to 10,the number of neurons in the 1st hidden layer was equal to 7,the number of neurons in the output layer was equal to 1,and the number of epochs was equal to 500.70%of the data were used for training and 30%for *** the designed artificial neural network,all experiment data except one were correctly predicted and the obtained MAE error was less than 0.012%.Finally,he precision and correction of the presented model was confirmed by the obtained results.

关键词： Burnout artificial neural network multi-layer perceptron COVID-19 resilience

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Selective toxicity of hydroxyl-rich carbon nanodots for cancer research

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Nano Research 2018年第4期11卷 2204-2216页

作者： Tak H. Kim Joseph P. Sirdaarta Qian Zhang ehsan eftekhari James St. John Derek Kennedy Ian E. Cock Qin Li Queensland Micro and Nano Technology Center & School of Engineering Griffith University 170 Kessels Rd Nathan OLD 4111 Australia Australian Rivers Institute & School of Natural Sciences Griffith University 170 Kessels Rd Nathan QLD 4111 Australia Griffith Institute for Drug Discovery Gfiffith University 46 Don Young Rd Nathan QLD 4111 Australia Menzies Health Institute Queensland Griffith University Parkland Drive Southport QLD 4222 Australia

The toxicity of nanoparticles in a biological system is an integration of effects arising from surface functionali~ particle size, ionic dissolution, etc. This complexity suggests that generalization of a material＇s toxicity may be inappropriate. Moreover, from a medicinal point of view, toxicity can be used for treatment of malignant cells, such as cancer. In this stud~ highly biocompatible carbon nanodots （gCDs） were synthesized by reacting citric acid and urea in glycerol, which resulted in abundant hydroxyl functional groups on the particle surface. gCDs show excitation-dependent photoluminescence but with bright green to yellow emission. Importantly, a series of toxicity assessments showed that as-synthesized gCDs possessed exceptional biocompatibilities to various biological entities including 18 bacteria species, Petunia axillaris seedlings, and Artemia franciscana nauplii. Furthermore, the particles were shown to have low to no toxic effects on human embryonic kidney （HEK-293）, breast （MCF-7）, and oral squamous （CAL-27） carcinoma cell lines. Of particular interest, the gCDs displayed antiproliferative activities against ovarian choriocarcinoma cells （JAr/Jeg-3 cell lines）, which may be further explored for cancer drug discovery.

关键词： carbon nanodots nanotoxicity fluorescence choriocarcinoma cells thioredoxin reductase

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添加不同量促腐熟菌剂对木屑和黄浆水堆肥的影响

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甘肃农业大学学报 2024年第2期59卷 117-126页

作者：杨娜马亚兰顾欣 eftekhari Ali Reza 李思琦李雪雪宁夏大学农学院宁夏银川750021

【目的】以木屑和黄浆水为原料,探讨促腐熟菌剂不同添加量对堆肥进程的影响。【方法】采用好氧发酵罐堆肥试验,设置不加促腐熟菌剂(T_(0))、加促腐熟菌剂质量分数0.1%(T_(1))、0.3%(T_(2))、0.9%(T_(3))共4个处理,以堆肥温度、pH值、种... 详细信息

【目的】以木屑和黄浆水为原料,探讨促腐熟菌剂不同添加量对堆肥进程的影响。【方法】采用好氧发酵罐堆肥试验,设置不加促腐熟菌剂(T_(0))、加促腐熟菌剂质量分数0.1%(T_(1))、0.3%(T_(2))、0.9%(T_(3))共4个处理,以堆肥温度、pH值、种子发芽指数、养分质量分数作为评价指标。采用主成分分析,研究促腐熟菌剂添加量对物料发酵进程和腐熟度的影响,明确最佳添加量。【结果】与T_(0)比较,添加促腐熟菌剂处理提前2 d进入高温期。发酵结束后,各处理的堆肥p H值介于7.46~7.74。添加不同质量分数的促腐熟菌剂可以不同程度地降低堆肥物料的碳、氮损失。与T_(0)相比,T_(1)、T_(2)、T_(3)氮损失分别降低9.41%、14.12%和4.71%,碳损失分别降低3.06%、7.97%和5.89%,其中T_(2)的氮、碳损失最低,分别为75.26%和7.82%。添加促腐熟菌剂的堆肥腐熟度比T_(0)提高3.64%~9.09%,T_(2)最先达到腐熟。【结论】综上所述,在木屑和黄浆水堆肥中添加质量分数0.3%的促腐熟菌剂,能显著促进物料腐熟,有利于降低氮、碳损失,提高堆肥质量,为木屑和黄浆水的肥料化利用提供了依据。

关键词：木屑促腐熟菌剂黄浆水堆肥发酵

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Mechanism Based Pharmacokinetic Pharmacodynamic Modeling of Vildagliptin as an Add-on to Metformin for Subjects with Type 2 Diabetes

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Computer Modeling in Engineering & Sciences 2018年第2期114卷 153-171页

作者： Marziyeh eftekhari Omid Vahidi School of Chemical Petroleum and Gas EngineeringIran University of Science and TechnologyNarmakTehranIran

Various drugs are used to maintain normoglycemia in subjects with type 2 diabetes *** combination of the drugs from different classes in one single tablet may enhance the effectiveness of the anti-diabetic *** investigate the impact of combining drugs on the glucose regulation of subjects with type 2 diabetes,we propose a pharmacokinetic/pharmacodynamics(PK/PD)mathematical modeling approach for a combination of metformin and vildagliptin *** the proposed modeling approach,two separate PK models representing oral administration of metformin and vildagliptin for diabetic subjects are interconnected to a PD model comprising a detailed compartmental physiological model representing the regulatory effect of insulin,incretins and glucagon hormones on glucose concentration in a human *** impact of doses of individual drugs and their combination on the blood glucose concentration of a group of type 2 diabetic subjects is *** is indicated that while administration of individual drugs reduces the blood glucose levels,since they have separate mechanisms of action,combining them synergizes lowering the blood glucose levels.

关键词： Pharmacokinetics pharmacodynamics mathematical modeling anti-diabetic drugs metformin vildagliptin

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Prediction of mode I fracture toughness of rock using linear multiple regression and gene expression programming

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第5期14卷 1421-1432页

作者： Bijan Afrasiabian Mosleh eftekhari Department of Mining Engineering Science and Research BranchIslamic Azad UniversityTehranIran Department of Mining Engineering Faculty of EngineeringTarbiat Modares UniversityTehranIran

Prediction of mode I fracture toughness(KIC) of rock is of significant importance in rock engineering analyses. In this study, linear multiple regression(LMR) and gene expression programming(GEP)methods were used to provide a reliable relationship to determine mode I fracture toughness of rock. The presented model was developed based on 60 datasets taken from the previous literature. To predict fracture parameters, three mechanical parameters of rock mass including uniaxial compressive strength(UCS), Brazilian tensile strength(BTS), and elastic modulus(E) have been selected as the input parameters. A cluster of data was collected and divided into two random groups of training and testing ***, different statistical linear and artificial intelligence based nonlinear analyses were conducted on the training data to provide a reliable prediction model of KIC. These two predictive methods were then evaluated based on the testing data. To evaluate the efficiency of the proposed models for predicting the mode I fracture toughness of rock, various statistical indices including coefficient of determination(R2),root mean square error(RMSE), and mean absolute error(MAE) were utilized herein. In the case of testing datasets, the values of R2, RMSE, and MAE for the GEP model were 0.87, 0.188, and 0.156,respectively, while they were 0.74, 0.473, and 0.223, respectively, for the LMR model. The results indicated that the selected GEP model delivered superior performance with a higher R2value and lower errors.

关键词： Mode I fracture Toughness Critical stress intensity factor Linear multiple regression(LMR) Gene expression programming(GEP)

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Quantum Correlations in Ising-XYZ Diamond Chain Structure under an External Magnetic Field

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Chinese Physics Letters 2015年第10期32卷 9-13页

作者： Faizi E. eftekhari H. Department of Physics Azerbaijan Shahid Madani University

We consider an entangled Ising-XY Z diamond chain structure. Quantum correlations for this model are inves- tigated by using quantum discord and trace distance discord. Quantum correlations are obtained for different values of the anisotropy parameter, magnetic field and temperature. By comparison between quantum correlations, we show that the trace distance discord is always larger than quantum discord. Finally, some novel effects such as increasing the quantum correlations with temperature and constructive role of anisotropy parameter, which may play to the quantum correlations, are observed.

关键词： TDD Quantum Correlations in Ising-XYZ Diamond Chain Structure under an External Magnetic Field

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Magnetic field effects on the nonlinear vibration of a rotor

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Applied Mathematics and Mechanics(English Edition) 2020年第2期41卷 289-312页

作者： M.eftekhari A.DASHTI-RAHMATABADI A.MAZIDI Department of Mechanical Engineering Yazd UniversityYazd 89195-741Iran

The nonlinear vibration of a rotor operated in a magnetic field with geometric and inertia nonlinearity is investigated. An asymmetric magnetic flux density is generated,resulting in the production of a load on the rotor since the air-gap distribution between the rotor and the stator is not uniform. This electromagnetic load is a nonlinear function of the distance between the geometric centers of the rotor and the stator. The nonlinear equation of motion is obtained by the inclusion of the nonlinearity in the inertia, the curvature, and the electromagnetic load. After discretization of the governing partial differential equations by the Galerkin method, the multiple-scale perturbation method is used to derive the approximate solutions to the equations. In the numerical results, the effects of the electromagnetic parameter load, the damping coefficient, the amplitude of the initial displacement, the mass moment of inertia, and the rotation speed on the linear and nonlinear backward and forward frequencies are investigated. The results show that the magnetic field has significant effects on the nonlinear frequency of oscillation.

关键词： nonlinear vibration in-extensional rotor nonlinear curvature gyroscopic effect magnetic field

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Mixed finite element and differential quadrature method for free and forced vibration and buckling analysis of rectangular plates

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Applied Mathematics and Mechanics(English Edition) 2012年第1期33卷 81-98页

作者： S. A. eftekhari A. A. JAFARI Department of Mechanical Engineering K. N. Toosi University of Technology

This paper presents a combined application of the finite element method （FEM） and the differential quadrature method （DQM） to vibration and buckling problems of rectangular plates. The proposed scheme combines the geometry flexibility of the FEM and the high accuracy and efficiency of the DQM. The accuracy of the present method is demonstrated by comparing the obtained results with those available in the literature. It is shown that highly accurate results can be obtained by using a small number of finite elements and DQM sample points. The proposed method is suitable for the problems considered due to its simplicity and potential for further development.

关键词： finite element method (FEM) differential quadrature method (DQM) rectangular plate free and forced vibration buckling analysis

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Texture evolution and mechanical anisotropy of an ultrafine/nano-grained pure copper tube processed via hydrostatic tube cyclic expansion extrusion

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International Journal of Minerals,Metallurgy and Materials 2022年第12期29卷 2241-2251页

作者： Seyed Moien Faregh Ghader Faraji Mahmoud Mosavi Mashhadi Mohammad eftekhari School of Mechanical Engineering College of EngineeringUniversity of TehranTehran 11155-4563Iran

Texture evolution and mechanical anisotropic behavior of an ultrafine-grained(UFG)pure copper tube processed by recently introduced method of hydrostatic tube cyclic expansion extrusion(HTCEE)was *** the UFG tube,different deformation behavior and a significant anisotropy in tensile properties were recorded along the longitudinal and peripheral *** HTCEE process increased the yield strength and the ultimate strength in the axial direction by 3.6 and 1.67 times,***,this process increased the yield strength and the ultimate strength in the peripheral direction by 1.15 and 1.12 times,*** ratio of ultimate tensile strength in the peripheral direction to that in the axial direction,as a criterion for mechanical anisotropy,are 1.7 and 1.16 for the as-annealed coarse-grained and the HTCEE processed UFG tube,*** results are indicative of a reducing effect of the HTCEE process on the mechanical ***,after HTCEE process,a low loss of ductility was observed in both directions,which is another advantage of HTCEE *** measurements revealed a slight increment of hardness values in the peripheral direction,which is in agreement with the trend of tensile *** analysis was conducted in order to determine the oriental distribution of the *** obtained{111}pole figures demonstrate the texture evolution and reaffirm the anisotropy observed in mechanical *** electron microscopy micrographs showed that different modes of fracture occurred after tensile testing in the two orthogonal directions.

关键词： severe plastic deformation ultrafine grained hydrostatic tube cyclic expansion extrusion anisotropy texture

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Mechanism of fracture in macro- and micro-scales in hollow centre cracked disc specimen

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Journal of Central South University 2015年第11期22卷 4426-4433页

作者： M.eftekhari A.Baghbanan H.Hashemolhosseini H.Amrollahi Department of Mining Engineering Isfahan University of Technology (IUT)

The hollow centre cracked disc(HCCD) specimen is one of the suggested alternative methods for determining the fracture toughness of rock. This work aims to investigate the fracture mechanism in HCCD in macro- and micro-scales using numerical methods, extended finite element method(X-FEM) and particle flow code(PFC) modeling, respectively. In the X-FEM, heaviside and near-tip enrichment functions are employed to consider the presence of the crack in the model. In PFC modeling the movement and interaction of stressed assemblies of rigid spherical particles are modeled using the distinct element method(DEM). A numerical code called MEX-FEM based on XFEM has been developed to simulate the problems involving crack. The models of pure modes I and Ⅱ in macro-scale are simulated in micro-scale. The results show that dimensionless stress intensity factors(YI, YⅡ) for pure modes I and Ⅱ increase by increasing the crack length ratio. The angle at which the pure mode Ⅱ occurs decreases by increasing the crack length ratio. In mixed mode I-Ⅱ, The value of YI decreases by increasing the crack angle, while the value of YⅡ increases to a given crack angle and then it decreases. Moreover, the fracture in micro-scale, unlike the macro-scale, includes a combination of different modes of fracturing.

关键词： hollow centre cracked disc(HCCD) extended finite e

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