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Predicting density log from well log using machine learning techniques and heuristic optimization algorithm:A comparative study

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Petroleum Research 2024年第2期9卷 176-192页

作者： mehdi rahmati Ghasem Zargar Abbas Ayatizadeh Tanha National Iranian Drilling Company Well Logging DepartmentAhwazIran Faculty Member of Petroleum University of Technology Iran Department of Petroleum Engineering Tarbiat Modares UniversityTehranIran

In the petroleum industry,the analysis of petrophysical parameters is critical for efficient reservoir management,production optimization,development strategies,and accurate hydrocarbon reserve *** recent years,the integration of machine learning methodologies has revolutionized the field,addressing challenges in geology,geophysics,and petroleum engineering,even when confronted with limited or imperfect *** study focuses on the prediction of density logs,a pivotal factor in evaluating reservoir hydrocarbon *** is important to note that during well logging operations,log data for specific depths of interest may be missing or incorrect,presenting a significant *** tackle this issue,we employed the Adaptive Neuro-Fuzzy Inference System(ANFIS)and Artificial Neural Networks(ANN)in combination with advanced optimization algorithms,including Particle Swarm Optimization(PSO),Imperialist Competitive Algorithms(ICA),and Genetic Algorithms(GA).These methods exhibit promising performance in predicting density logs from gamma-ray,neutron,sonic,and photoelectric log ***,our results highlight that the Genetic Algorithms-based Artificial Neural Network(GA-ANN)approach outperforms all other methods,achieving an impressive Mean Squared Error(MSE)of *** comparison,ANFIS records an MSE of 0.0015,ICA-ANN 0.0090,PSO-ANN 0.0093,and ANN 0.0183.

关键词： Density log Machine learning approaches Artificial neural networks(ANN) Adaptive neuro-fuzzy inference system(ANFIS) Optimization algorithm

A rapid and efficient method for the synthesis of 14H-dibenzo[α.j]xanthenes,aryl-5H-dibenzo[b.i]xanthene-5,7,12,14-(13H)-tetraone and 1,8-dioxooctahydroxanthenes by acidic ionic liquid

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Chinese Chemical Letters 2010年第7期21卷 761-764页

作者： Abbas rahmati Department of Chemistry University of IsfahanP.O.Box 81746-7344IsfahanIran

Various xanthenes have been synthesized by the condensation ofβ-naphthol,2-hydroxynaphthalene-1,4-dione or dimedone with various aldehydes in the presence of trifluoroacetic acid as catalyst in 1,1,3,3-N,N,N′,N′-te... 详细信息

关键词： Ionic liquid 14H-Dibenzo[α.j]xanthenes β-Naphthol 2-Hydroxynaphthalene-1 4-dione Dimedone

On intervals and sets of hypermatrices(tensors)

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Frontiers of Mathematics in China 2020年第6期15卷 1175-1188页

作者： Saeed rahmati Mohamed A.TAWHID Department of Mathematics and Statistics Faculty of ScienceThompson Rivers UniversityKamloopsBC V2C 0C8Canada

Interval hypermatrices(tensors)ape introduced and interval α-hypermatrices are uniformly characterized using a finite set of'extreme'hypermatrices,where α can be strong P,semi-positive,or positive definite,among many *** is shown that a symmetric interval is an interval(strictly)copositive-hypermatrix if and only if it is an interval(E)*** is also shown that an even-order,symmetric interval is an interval positive(semi-)definite-hypermatrix if and only if it is an interval P(P_(0))-*** hypermnatrices are generalized to sets of hyper-matrices,several slice-properties of a set of hypermatrices are introduced and sets of hypermatrices with various slice-properties are uniformly *** a consequence,several slice-properties of a compact,convex set of hyper-matrices are characterized by its extreme points.

关键词： Tensor hypermatrix interval hypermatrix hypermatrix set slice-P-property

Squeezing rock conditions at phyllite-slate zone in Golab water conveyance tunnel,Iran:A case study

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Journal of Central South University 2017年第10期24卷 2475-2485页

作者： rahmati Asghar Faramarzi Lohrasb Darbor Mohammad Department of Mining Engineering Isfahan University of TechnologyIsfahan84156-83111Iran

Squeezing ground in tunneling is associated with large deformation of the tunnel face. In this study, squeezing characteristics of the ground and rock conditions in Golab water conveyance tunnel, Iran, are discussed and the classification of squeezing behavior around zones where the problems occurred is presented. The squeezing conditions were investigated using empirical and semi empirical methods. In the next step, creep convergence of the tunnel with Burger's model was simulated by the numerical method. Numerical analysis showed that wall displacement(64.1 mm) of the Golab tunnel was more than allowable strain(1% of the tunnel diameter), therefore, it was found that squeezing phenomenon could exist, leading to the failure of the support system. Numerical analysis at the phyllite-slate zone also showed squeezing conditions due to the weakness of rock mass and high overburden that this situation cause failure in the segmental lining. In this research, failure in segmental lining in phyllite-slate zone verified the results of the numerical modeling.

关键词： squeezing large deformation Burger’s model numerical analysis failure segmental lining

On Non-standard Hilbert Functions

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Algebra Colloquium 2018年第1期25卷 71-80页

作者： Amir Bagheri Rahim rahmati-Asghar Marand Technical Coflege University of Tabriz Tabriz Iran School of Mathematics Institute for Research in Fundamental Sciences (IPM) Department of Mathematics Faculty of Basic Sciences University of Maragheh

. Let S = k[x1,..., xn] be a non-standard polynomial ring over a field k and let M be a finitely generated graded S-module. In this paper, we investigate the behaviour of Hilbert function of M and its relations with lattice point counting. More precisely, by using combinatorial tools, we prove that there exists a polytope such that the image of Hilbert function in some degree is equal to the number of lattice points of this polytope.

关键词： polynomial ring non-standard Hilbert function Hermite normal form

Catalyst free synthesis of fused pyrido[2,3-d]pyrimidines and pyrazolo[3,4-b]pyridines in water

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Chinese Chemical Letters 2012年第10期23卷 1149-1152页

作者： Abbas rahmati Zahra Khalesi Department of Chemistry University of IsfahanP.O.Box 8174673441 IsfahanIran

A one-pot, three-component condensation reaction of an aldehyde, benzoyl acetonitrile （3-oxo-3-phenylpropane nitrile） and 6- amino-1,3-dimethylpyrimidine-2,4（1H,3H）-dione or 3-methyl-l-phenyl-lH-pyrazol-5-amine in water to give fused pyrido[2,3- d]pyrimidines and pyrazolo[3,4-b]pyridines in high yields without any catalyst, is described.

关键词： Aminopyrazole Aqueous media 3-Methyl-l-phenyl-lH-pyrazol-5-amine Pyrazolo[3,4-b]pyridine

Microwave-induced Stereoselectivity in Synthesis of trans-4-Aryl-3-methyl-6-oxo-4,5,6,7-tetrahydro-2H- pyrazolo[3,4-b]pyridine-5-carbonitriles

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Chinese Journal of Chemistry 2011年第11期29卷 2373-2378页

作者： rahmati, Abbas Alizadeh Kouzehrash, Meysam Department of Chemistry University of lsfahan P. O. Box 81746-7344 Isfahan Iran

A facile synthesis of trans isomers of 4-aryl-3-methyl-6-oxo-4,5,6,7-tetrahydro-2H-pyrazolo[3,4-b]pyridine-5- carbonitriles via three-component condensation reaction of an aldehyde, 3-amino-5-methylpyrazole and ethyl cyanoacetate in acetonitrile has been developed under microwave irradiation. This one-pot reaction proceeds with-out any catalyst in short times and gives the product in high selectivities and high yields.

关键词： multi-component condensation reactions microwave pyrazolo[3,4-b]pyridine 3-amino-5- methylpyrazole

Revisiting the space-time gradient method:A time-clocking perspective, high order difference time discretization and comparison with the harmonic balance method

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Chinese Journal of Aeronautics 2022年第11期35卷 45-58页

作者： Boqian WANG Dingxi WANG Mohammad rahmati Xiuquan HUANG School of Power and Energy Northwestern Polytechnical UniversityXi'an 710072China Department of Mechanical and Construction Engineering Northumbria UniversityNewcastle upon Tyne NEI 8STUnited Kingdom

This paper revisits the Space-Time Gradient(STG) method which was developed for efficient analysis of unsteady flows due to rotor–stator interaction and presents the method from an alternative time-clocking perspective. The STG method requires reordering of blade passages according to their relative clocking positions with respect to blades of an adjacent blade row. As the space-clocking is linked to an equivalent time-clocking, the passage reordering can be performed according to the alternative time-clocking. With the time-clocking perspective, unsteady flow solutions from different passages of the same blade row are mapped to flow solutions of the same passage at different time instants or phase angles. Accordingly, the time derivative of the unsteady flow equation is discretized in time directly, which is more natural than transforming the time derivative to a spatial one as with the original STG method. To improve the solution accuracy, a ninth order difference scheme has been investigated for discretizing the time derivative. To achieve a stable solution for the high order scheme, the implicit solution method of Lower-Upper Symmetric GaussSeidel/Gauss-Seidel(LU-SGS/GS) has been employed. The NASA Stage 35 and its blade-countreduced variant are used to demonstrate the validity of the time-clocking based passage reordering and the advantages of the high order difference scheme for the STG method. Results from an existing harmonic balance flow solver are also provided to contrast the two methods in terms of solution stability and computational cost.

关键词： Harmonic balance method High order difference scheme Passage reordering Space-time gradient method Unsteady flows

A sensorless and simple controller for VSC based HVDC systems

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第12期10卷 1824-1834页

作者： E. ABIRI A. rahmati A. ABRISHAMIFAR Department of Electronic and Electrical Engineering Shiraz University of Technology Department of Electronic and Electrical Engineering Iran University of Science and Technology

Voltage source converter high-voltage direct current （VSC-HVDC） is a new power transmission technology pref- erable in small or medium power transmission. In this paper we discuss a new control system based on space vector modulation （SVM） without any voltage line sensors. Using direct power control （DPC） SVM and a new double synchronous reference frame phase-locked loop （DSRF-PLL） approach, the control system is resistant to the majority of line voltage disturbances. Also, the system response has accelerated by using a feed forward power decoupled loop. The operation of this control strategy was verified in a SIMULINK/MATLAB simulation environment. To validate this control system, a 5 kV.A prototype system was constructed. Compared to the original controllers, the current total harmonic distortion （THD）, the active and reactive deviations and the DC voltage overshoot were lowered by 2.5%, 6.2% and 8%, respectively. The rectifier power factor in the worst condition was 0.93 and the DC voltage settling time was 0.2 s.

关键词： Voltage source converter high-voltage direct current (VSC-HVDC) Space vector modulation (SVM) Direct power control (DPC) HVDC Light