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Cluj Napoca, Romania

The Technical University of Cluj-Napoca is a public university located in Cluj-Napoca, Romania. It was founded in 1948, based on the older Industrial College . Wikipedia.

Nedelcu M.,Technical University of Cluj Napoca
Thin-Walled Structures | Year: 2012

This paper presents an original method based on the Generalised Beam Theory (GBT) capable to decompose the elastic buckling modes from a shell finite element analysis (FEA) of an isotropic thin-walled member, into pure buckling modes of global, distorsional or local nature. The main novelty lies in using only the GBT cross-sectional deformation modes instead of member base mode shapes. The contribution of each pure buckling mode can be calculated, allowing a better understanding of the member post-buckling behaviour and strength reserve. Following the GBT classical assumptions, the membrane shear strains and transverse extensions are neglected. The modal participations obtained from FEA are in good agreement with the values calculated via classical GBT approach. © 2012 Elsevier Ltd. Source

Berinde V.,Technical University of Cluj Napoca
Computers and Mathematics with Applications | Year: 2012

We obtain coupled coincidence and coupled common fixed point theorems for mixed g-monotone nonlinear operators F:X×X→X in partially ordered metric spaces. Our results are generalizations of recent coincidence point theorems due to Lakshmikantham and irić [V. Lakshmikantham, L. irić, Coupled fixed point theorems for nonlinear contractions in partially ordered metric spaces, Nonlinear Anal. 70 (2009) 4341-4349], of coupled fixed point theorems established by Bhaskar and Lakshmikantham [T.G. Bhaskar, V. Lakshmikantham, Fixed point theorems in partially ordered metric spaces and applications, Nonlinear Anal. 65 (7) (2006) 1379-1393] and also include as particular cases several related results in very recent literature. © 2012 Elsevier Ltd. All rights reserved. Source

Rosca D.,Technical University of Cluj Napoca
Astronomy and Astrophysics | Year: 2010

Aims. A method for constructing new uniform grids on the sphere is given. Methods. We define a bijection in R2, which maps squares onto discs and preserves areas. Then we use this bijection, combined with Lambert azimuthal projection, for lifting uniform grids from the square to the sphere. Results. We can obtain uniform spherical grids that allow a hierarchical data manipulation and have an isolatitudinal distribution of cells. Compared with HEALPix grids, nowadays the most used in astronomy and astrophysics, our grids have the advantage of allowing easier implementation, and in addition one can move approximating functions from the square to the sphere by a simple technique. © 2010 ESO. Source

Lazarescu L.,Technical University of Cluj Napoca
International Journal of Advanced Manufacturing Technology | Year: 2013

In the present study, the rotary draw bending of aluminum alloy tubes with internal fluid pressure is investigated by finite element simulation and experiments. The effect of the internal pressure on the cross-section ovality, wall thinning, and wall thickening was studied. The results show that the internal pressure has a significant effect on cross-section quality of aluminum alloy bent tubes. As the internal pressure increases, the cross-section ovality and the wall thickening decrease, and the wall thinning increases. The effect of internal pressure on wall thinning is more significant than its effect on wall thickening. © 2012 Springer-Verlag London Limited. Source

Objective: The purpose of this paper is to determine a quantitative assessment of the human retinal vascular network architecture for patients with diabetic macular edema (DME). Multifractal geometry and lacunarity parameters are used in this study. Materials and methods: A set of 10 segmented and skeletonized human retinal images, corresponding to both normal (five images) and DME states of the retina (five images), from the DRIVE database was analyzed using the Image J software. Statistical analyses were performed using Microsoft Office Excel 2003 and GraphPad InStat software. Results: The human retinal vascular network architecture has a multifractal geometry. The average of generalized dimensions (Dq) for q = 0, 1, 2 of the normal images (segmented versions), is similar to the DME cases (segmented versions). The average of generalized dimensions (Dq) for q = 0, 1 of the normal images (skeletonized versions), is slightly greater than the DME cases (skeletonized versions). However, the average of D2 for the normal images (skeletonized versions) is similar to the DME images. The average of lacunarity parameter, Λ, for the normal images (segmented and skeletonized versions) is slightly lower than the corresponding values for DME images (segmented and skeletonized versions). Conclusion: The multifractal and lacunarity analysis provides a non-invasive predictive complementary tool for an early diagnosis of patients with DME. © Informa Healthcare USA, Inc. Source

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