7 articles for “numerical radius”

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Research ArticleOpen accessIn the keywordsOn Numerical Ranges of Nilpotent Elements of C*-AlgebraA. Abdollahi, M. T. Heydari, M. MoosaviProblem statement: Let A be a C*-algebra with unit 1. For each a∈A, let V(a), v(a) v0(a) and denote its numerical range, numerical radius and the distance from the origin to the boundary of its numerical range, respectively. Approach: If a is a nilpotent element of A with the power of nilpotency n, i.e., an = 0 and v(a) = … …Journal of Mathematics and Statistics, Vol. 5, Issue 4 · 31 Dec 2009 · 7,437 accessesView PDF Cite

Research ArticleOpen accessIn the abstractAnalytical Solution Based on a New Series along with the Numeric Solution of the Non-Homogeneous Transient Heat Conduction Equation, in Hollow Cylinder under General Mixed Boundary ConditionsMehdi Zare, F. KardanIn this study, the problem of transient conduction heat transfer for an infinite hollow cylinder under non-homogeneous mixed boundary conditions at the both surfaces simultaneously in radial direction with general heat source depend on time and radius, also general initial condition by the method of superposition and separation variables, is solved and temperature distribution is obtained analytically. A new series … …American Journal of Engineering and Applied Sciences, Vol. 11, Issue 2 · 20 Apr 2018 · 9,486 accessesView PDF Cite

Research ArticleOpen accessIn the abstractDevelopment of a Magnetorheological Finishing Machine for Small-Bore Part of Irregular Shape and Experimental StudyWang Tingzhang, Chen Mingjun, Liu Henan, Xu JiangMagnetorheological finishing machine tool with small ball-end permanent-magnet polishing head is proposed as a method to solve the problem that small-bore parts of irregular shape with small curvature radius concave surface cannot be polished by traditional magnetorheological finishing machine tool. The four-axis linkage magnetorheological finishing machine tool with modular open numerical system and easy-operating man-machine interactive interface is developed. Then … …American Journal of Engineering and Applied Sciences, Vol. 8, Issue 3 · 26 Jun 2015 · 7,693 accessesView PDF Cite

Research ArticleOpen accessIn the abstractLaser-Induced Breakdown and Detonation in Particle-Laden SystemsKonstantin VolkovSimulation of the interaction of a laser pulse with gas-droplet and gas-particle mixtures plays an important role in environmental and engineering applications. The injection of liquid droplets or metal particle causes optical breakdown on the individual droplet or particle and leads to a drop of the detonation minimum pulse energy of the mixture. Mathematical models of various stages of the … …American Journal of Applied Sciences, Vol. 12, Issue 1 · 4 Mar 2015 · 7,348 accessesView PDF Cite

Research ArticleOpen accessIn the abstractDesign, Development and Numerical Analysis of Honeycomb Core with Variable Crushing StrengthShabnam Sadeghi Esfahlani, Hassan Shirvani, Ayoub Shirvani et al.A honeycomb core with half-circular cut-away sections at the spine (the adjoining cell walls) is designed and developed and numerically tested under axial dynamic load condition. The parametric study is invoked to identify the effect of various circular cut-away dimensions. In one embodiment a half-circular shaped cuts are removed from the top of the cell where the cell is impacted … …American Journal of Engineering and Applied Sciences, Vol. 6, Issue 1 · 15 Jan 2013 · 7,572 accessesView PDF Cite

Research ArticleOpen accessIn the abstractHemisphere Sizing from Linear Intercept MeasurementWilfried GilleThe stereological problem of unfolding the hemisphere radius distribution from the chord length distribution is analyzed. Let a stationary isotropic process of hemispheres be given. The hemispheres have random diameters and are isotropically uniformly randomly orientated in space. A straight line probe yields a process of intercepts. The inverse problem of re-obtaining the size distribution of the hemispheres in terms … …Journal of Mathematics and Statistics, Vol. 1, Issue 3 · 30 Sep 2005 · 6,146 accessesView PDF Cite

Research ArticleOpen accessAll words, across the recordAnalytical and Numerical Analysis of Free Bulge Tube HydroformingF. Djavanroodi, M. Gheisary, H. Zoghi-shalFree bulge hydroforming simulation was analysied to investigate the biaxial behavior of extruded aluminum tubes. A finite element model was constructed to simulate the hydroforming process and asses the influence of friction between die walls and tube, tube material properties and springback of formed tube. It was found that material hardening coefficient had the most significant influence on formability characteristics … …American Journal of Applied Sciences, Vol. 5, Issue 8 · 31 Aug 2008 · 6,863 accessesView PDF Cite