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Reduction of Ideals Relative to an Artinian Module and the Dual of Burch,s Inequality

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Algebra Colloquium 2019年第1期26卷 113-122页

作者： Fatemeh Cheraghi amir mafi Department of Mathematics University of Kurdistan P.O. Box: 416 Sanandaj Iran

Let (A,m) be a commutative quasi-local ring with non-zero identity and M be an Artinian A-module with dim M = d. If I is an ideal of A with l(0 :m I) 0. Moreover, we study the dual of Burch's inequality. In particular... 详细信息

关键词： reduction of ideals Artinian modules co-Cohen-Macaulay

Property of Almost Cohen-Macaulay over Extension Modules

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Algebra Colloquium 2017年第3期24卷 509-518页

作者： Samaneh Tabejamaat amir mafi Khadijeh Ahmadi Amoli Department of Mathematics Payame Noor University P.O.Box: 19395-3697 Tehran Iran Department of Mathematics University of Kurdistan P.O. Box: 416 Sanandaj Iran Department of Mathematics Payame Noor University P.O.Box: 19395-3697 Tehraa Iran

Let （R, m） be a Cohen-Macaulay local ring of dimension d, C a canonical R-module and M an almost Cohen-Macaulay R-module of dimension n and of depth t. We prove that dim Extd-n R（M,C） = n and if n ≤ 3 then Extd-n（M,C） is an almost Cohen-Macaulay R-module. In particular, if n = d ≤ 3 then HomR（M, C） is an almost Cohen-Macaulay R-module. In addition, with some conditions, we show that Ext1R（M, C） is also almost Cohen-Macaulay. Finally, we study the vanishing Ext2R （Extd-n （M, C）, C） and Ext2R （Extd-n（M, C）, C）.

关键词： almost Cohen-Macaulay module Ext functor finiteness dimension

A Characterization of Sequentially Cohen-Macaulay Matroidal Ideals

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Algebra Colloquium 2023年第2期30卷 237-244页

作者： Payman Mahmood Hamaali amir mafi Hero Saremi Department of Mathematics College of ScienceUniversity of Sulaimani SulaimanyahKurdistan RegionIraq Department of Mathematics University of Kurdistan P.O.Box:416SanandaIran Department of Mathematics Sanandaj Branch Islamic Azad UniversitySanandajIran

Let R=K[x1,…,xn]be the polynomial ring in n variables over a field K and I be a matroidal ideal of *** show that I is sequentially Cohen-Macaulay if and only if the Alexander dual Iy has linear *** a consequence,I is... 详细信息

关键词： sequentially Cohen-Macaulay monomial ideals matroidal ideals

CSRWA:Covert and Severe Attacks Resistant Watermarking Algorithm

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Computers, Materials & Continua 2025年第1期82卷 1027-1047页

作者： Balsam Dhyia Majeed amir Hossein Taherinia Hadi Sadoghi Yazdi Ahad Harati Faculty of Engineering Ferdowsi University of MashhadMashhad***Iran Department of Computer Techniques Engineering Imam Al-Kadhum CollegeBaghdad10087Iraq

Watermarking is embedding visible or invisible data within media to verify its authenticity or protect *** watermark is embedded in significant spatial or frequency features of the media to make it more resistant to intentional or unintentional *** of these features are important perceptual features according to the human visual system(HVS),which means that the embedded watermark should be imperceptible in these ***,both the designers of watermarking algorithms and potential attackers must consider these perceptual features when carrying out their *** two roles will be considered in this paper when designing a robust watermarking algorithm against the most harmful attacks,like volumetric scaling,histogram equalization,and non-conventional watermarking attacks like the Denoising Convolution Neural Network(DnCNN),which must be considered in watermarking algorithm design due to its rising role in the state-of-the-art *** DnCNN is initialized and trained using watermarked image samples created by our proposed Covert and Severe Attacks Resistant Watermarking Algorithm(CSRWA)to prove its *** this algorithm to satisfy the robustness and imperceptibility tradeoff,implementing the Dither Modulation(DM)algorithm is boosted by utilizing the Just Noticeable Distortion(JND)principle to get an improved performance in this ***,luminance,inter and intra-block contrast are used to adjust the JND values.

关键词： Covert attack digital watermarking DnCNN JND perceptual model robustness

CFD simulation of impeller shape effect on quality of mixing in two-phase gas–liquid agitated vessel

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Chinese Journal of Chemical Engineering 2020年第11期28卷 2733-2745页

作者： amir Heidari Process Simulation and Modeling Laboratory(PSMlab) Faculty of ChemicalPetroleum and Gas EngineeringSemnan UniversitySemnan ***Iran

Mixing efficiency in two-phase gas–liquid agitated vessel is one of the important challenges in the industrial *** fluid dynamics technique(CFD)was used to investigate the effect of four different pitched blade impellers,including 15°,30°,45°and 60°,on the mixing quality of gas–liquid agitated *** multiphase flow behavior was modeled by Eulerian–Eulerian multiphase approach,and RNG k-εwas used to model the *** CFD results showed that a strong global vortex plays the main role on the mixing quality of the gas phase in the *** on the standard deviation criterion,it was observed that the axial distribution of the gas phase in the 30°impeller is about 55%better than the *** addition,the results showed that the 30°impeller has a uniform radial distribution over the other impellers and the maximum gas phase holdup in the *** of the power consumption of the impellers showed that the 30°impeller has the highest power consumption among the other pitched blade ***,examine the effect of same power condition for pitched blade impellers showed that the 30°impeller has the best mixing quality in this condition.

关键词： Pitched blade impeller Mixing CFD Multiphase flow RNG k-εmodel

Phase-plane analysis of test particle orbits in regular black holes

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Communications in Theoretical Physics 2020年第1期72卷 111-117页

作者： Muhammed amir Astrophysics and Cosmology Research Unit School of MathematicsStatistics and Computer ScienceUniversity of KwaZulu-NatalPrivate Bag X54001Durban 4000South Africa

We investigate phase-plane analysis of general relativistic orbits in a gravitational field of the Reissner–Nordstr?m-type regular black hole *** employ phase-plane analysis to obtain different phase-plane diagrams of the test particle orbits by varying charge q and dimensionless parameterβ,whereβcontains angular momentum of the test *** compute numerical values of radii for the innermost stable orbits and corresponding values of energy required to place the test particle in *** on,we employ similar analysis on an Ayón–Beato–García(ABG)regular black hole and a comparison regarding key results is also included.

关键词： black holes modified gravity phase-plane diagrams

Computer-aided design of classical linear compensators with application to aerospace

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Journal of Systems Engineering and Electronics 2009年第6期20卷 1373-1377页

作者： amir Nassirharand School of Mechanical Manufacturing & Materials Engineering Univ.of Nottingham-Malaysia Campus Semenyih 43500 Malaysia

A new Matlab function based on a versatile compensator design approach is *** function allows design of lead-lag, PID, proportional plus rate feedback, proportional-integral plus rate feedback, and nth order linear *** primary inputs to this function are the plant transfer function and the desired closedloop behavior in terms of an nth order transfer *** output is the particular compensator *** unified design approach is primarily based on minimizing a mean-squared error type objective *** minimization gives the compensator parameters in terms of a set of linear simultaneous algebraic *** solution method requires the user to input such parameters as the lower and upper limits of frequency range of interest;such parameters are automatically determined by the use of numerical *** design method and the associated software are demonstrated by solving a flexible satellite problem, and the results are compared with those obtained by two other methods reported in the open literatures.

关键词： linear systems classical control numerical analysis optimization.

Multi-range controller design for highly nonlinear systems with application to unmanned aerial vehicles

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Journal of Systems Engineering and Electronics 2010年第3期21卷 491-495页

作者： amir Nassirharand School of Mechanical Manufacturing & Materials EngineeringUniversity of Nottingham-Malaysia Campus

A new procedure for a design of multi-range controllers for use with highly nonlinear systems is *** procedure involves obtaining the describing function models of the nonlinear plant by software followed by designing a controller at nominal ***,the controller parameters are optimized to yield a satisfactory closed-loop response at all operating ***,the performance and stability of the closed-loop system comprised of the designed controller and the nonlinear plant are *** procedure and the associated software are applied to a nonlinear control problem of the sort encountered in aerospace,and the results are compared with two other approaches.

关键词： control theory optimization describing functions Fourier analysis stabilization.

General Energy Decay of Solutions for a Weakly Dissipative Kirchhoff Equation with Nonlinear Boundary Damping

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Acta Mathematicae Applicatae Sinica 2017年第2期33卷 401-408页

作者： amir Peyravi Department of Mathematics College of Sciences Shiraz University Shiraz 71467-13565 Iran

In this article, we study the weak dissipative Kirchhoff equation under nonlinear damping on the boundary We prove a general energy decay property for solutions in terms of coefficient of the frictional boundary damping. Our result extends and improves some results in the literature such as the work by Zhang and Miao （2010） in which only exponential energy decay is considered and the work by Zhang and Huang （2014） where the energy decay has been not considered.

关键词： Kirchhoff equation general decay boundary damping