689 research outputs found

    Multi-objective optimization of carbon/glass hybrid composites with newly developed resin (NDR) using gray relational analysis

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    Purpose: It is seen that little amount of work on optimization of mechanical properties taking into consideration the combined effect of design variables such as stacking angle, stacking sequence, different resins and thickness of composite laminates has been carried out. The focus of this research work is on the optimization of the design variables like stacking angle, stacking sequence, different resins and thickness of composite laminates which affect the mechanical properties of hybrid composites. For this purpose, the Taguchi technique and the method of gray relational analysis (GRA) are used to identify the optimum combination of design variables. In this case, the effect of the abovementioned design variables, particularly of the newly developed resin (NDR) on mechanical properties of hybrid composites has been investigated. Design/methodology/approach: The Taguchi method is used for design of experiments and with gray relational grade (GRG) approach, the optimization is done. Findings: From the experimental analysis and optimization study, it was seen that the NDR gives excellent bonding strength of fibers resulting in enhanced mechanical properties of hybrid composite laminates. With the GRA method, the initial setting (A3B2C4D2) was having GRG 0.866. It was increased by using a new optimum combination (A2B2C4D1) to 0.878. It means that there is an increment in the grade by 1.366%. Therefore, using the GRA approach of analysis, design variables have been successfully optimized to achieve enhanced mechanical properties of hybrid composite laminates. Originality/value: This is an original research work

    Multi-frame scene-flow estimation using a patch model and smooth motion prior

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    This paper addresses the problem of estimating the dense 3D motion of a scene over several frames using a set of calibrated cameras. Most current 3D motion estimation techniques are limited to estimating the motion over a single frame, unless a strong prior model of the scene (such as a skeleton) is introduced. Estimating the 3D motion of a general scene is difficult due to untextured surfaces, complex movements and occlusions. In this paper, we show that it is possible to track the surfaces of a scene over several frames, by introducing an effective prior on the scene motion. Experimental results show that the proposed method estimates the dense scene-flow over multiple frames, without the need for multiple-view reconstructions at every frame. Furthermore, the accuracy of the proposed method is demonstrated by comparing the estimated motion against a ground truth

    Anisotropic flow from Lee-Yang zeroes: a practical guide

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    We present a new method to analyze anisotropic flow from the genuine correlation among a large number of particles, focusing on the practical implementation of the method.Comment: 4 pages; contribution to Quark Matter 2004, Oakland, January 11-17, 200

    Genuine collective flow from Lee-Yang zeroes

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    We propose to use the theory of phase transitions of Lee and Yang as a practical tool to analyze long-range correlations in a finite-size system. We apply it to the analysis of anisotropic flow in nucleus-nucleus collisions, and show that this method is more reliable than any other used so far.Comment: 5 pages, 3 eps figures, RevTeX. v2: overall presentation modifie

    Directed flow at RHIC from Lee-Yang zeroes

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    Directed flow in ultrarelativistic nucleus-nucleus collisions is analyzed using the reaction plane from elliptic flow, which reduces the bias from nonflow effects. We combine this method with the determination of elliptic flow from Lee-Yang zeroes. The resulting method is more consistent and somewhat easier to implement than the previously used method based on three-particle cumulants, and is also less biased by nonflow correlations. Error terms from residual nonflow correlations are carefully estimated, as well as statistical errors. We discuss the application of the method at RHIC and LHC.Comment: 10 pages. Final version, to appear in Nucl. Phys.

    Study on initial geometry fluctuations via participant plane correlations in heavy ion collisions: part II

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    Further investigation of the participant plane correlations within a Glauber model framework is presented, focusing on correlations between three or four participant planes of different order. A strong correlation is observed for cos⁡(2Ω2∗+3Ω3∗−5Ω5∗)\cos(2\Phi_{2}^*+3\Phi_{3}^*-5\Phi_{5}^*) which is a reflection of the elliptic shape of the overlap region. The correlation between the corresponding experimental reaction plane angles can be easily measured. Strong correlations of similar geometric origin are also observed for cos⁡(2Ω2∗+4Ω4∗−6Ω6∗)\cos(2\Phi_{2}^*+4\Phi_{4}^*-6\Phi_{6}^*), cos⁡(2Ω2∗−3Ω3∗−4Ω4∗+5Ω5∗)\cos(2\Phi_2^*-3\Phi_3^*-4\Phi_4^*+5\Phi_5^*), cos⁡(6Ω2∗+3Ω3∗−4Ω4∗−5Ω5∗)\cos(6\Phi_2^*+3\Phi_3^*-4\Phi_4^*-5\Phi_5^*), cos⁡(Ω1∗−2Ω2∗−3Ω3∗+4Ω4∗)\cos(\Phi_1^*-2\Phi_2^*-3\Phi_3^*+4\Phi_4^*), cos⁡(Ω1∗+6Ω2∗−3Ω3∗−4Ω4∗)\cos(\Phi_1^*+6\Phi_2^*-3\Phi_3^*-4\Phi_4^*), and cos⁡(Ω1∗+2Ω2∗+3Ω3∗−6Ω6∗)\cos(\Phi_1^*+2\Phi_2^*+3\Phi_3^*-6\Phi_6^*), which are also measurable. Experimental measurements of the corresponding reaction plane correlators in heavy ion collisions at RHIC and the LHC may improve our understanding of the physics underlying the measured higher order flow harmonics.Comment: 5 pages, 5 figure

    Optimization of design variables for carbon/glass hybrid composites laminates using the Taguchi Technique

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    The purpose of this paper is to analyze the significance of disparate design variables on the mechanical properties of the composite laminate. Four design variables such as stacking sequence, stacking angle, types of resins and thickness of laminate have been chosen to analyze the impact on mechanical properties of the composite laminate. The detailed investigation is carried out to analyze the effect of a carbon layer in stacking sequence and investigate the impact of various resins on the fastening strength of fibers, stacking angles of the fibers and the thickness of the laminate

    Principle of Balance and the Sea Content of the Proton

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    In this study, the proton is taken as an ensemble of quark-gluon Fock states. Using the principle of balance that every Fock state should be balanced with all of the nearby Fock states (denoted as the balance model), instead of the principle of detailed balance that any two nearby Fock states should be balanced with each other (denoted as the detailed balance model), the probabilities of finding every Fock state of the proton are obtained. The balance model can be taken as a revised version of the detailed balance model, which can give an excellent description of the light flavor sea asymmetry (i.e., uˉ=Ìždˉ\bar{u}\not= \bar{d}) without any parameter. In case of g⇔ggg\Leftrightarrow gg sub-processes not considered, the balance model and the detailed balance model give the same results. In case of g⇔ggg\Leftrightarrow gg sub-processes considered, there is about 10 percent difference between the results of these models. We also calculate the strange content of the proton using the balance model under the equal probability assumption.Comment: 32 latex pages, 4 ps figures, to appear in PR
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