1,490 research outputs found

    Classical solution of the Cauchy problem for biwave equation: Application of Fourier transform

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    In this paper, we use some Fourier analysis techniques to find an exact solution to the Cauchy problem for the nn-dimensional biwave equation in the upper half-space Rn×[0,+∞)\mathbb{R}^n\times [0,+\infty).Comment: 11 page

    Corporate Governance Structures and Performance of Firms in Asian Markets: a Comparative Analysis Between Singapore and Vietnam

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    A cross-country comparative analysis of corporate governance structures and financial performance of publicly listed companies in Singapore and Vietnam, covering a four-year period from 2008 to 2011, is undertaken in this study. More specifically, the similarities and differences in the corporate governance structures and financial performance of the companies are compared and interpreted in the institutional context of each market. On an average basis, we find that the size, composition and diversity of the boards in these two markets are statistically significantly different. In contrast, there is no statistical evidence to reject the similarities in ownership structure, board leadership structure, and financial performance between the firms of the two markets. In addition, our comparative analysis on the corporate governance structures–financial performance nexus also reveals that the performance effects of corporate governance structures vary significantly between the two markets, thus supporting the view that the performance effects of corporate governance structures are country-specific. Our findings suggest that country-level characteristics should be captured when modelling the corporate governance–firm performance relationship in cross-country comparative corporate governance research

    Enhancing the ride comfort of the off-road vibratory roller cab by adding damper hydraulic mount

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    In order to improve the vibratory roller’s ride comfort, a 3-D nonlinear dynamic model of the vehicle interacting with the off-road terrain is established. A damper hydraulic mount is studied and combined with the cab’s rubber mounts to simulate and evaluate the performance of the ride comfort. The weighted RMS acceleration responses of the vertical driver’s seat, the cab’s pitch and roll angle are chosen as objective functions. The results show that the cab’s rubber mounts combined with the damper hydraulic mount are clearly improved the ride comfort under various operating conditions. Especially, with damping coefficients cc3,4= 1.8 kN.s.m-1, the weighted RMS values of the vertical driver’s seat, the cab’s pitch and roll angle are greatly reduced by 27.8 %, 22.7 % and 64.3 % in condition of the vehicle traveling, and by 23.8 %, 20.0 % and 63.7 % in condition of the vehicle compacting on an elastic-plastic terrain

    Evaluating the effect of the working conditions on the ride comfort and road friendliness of the heavy truck

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    This study proposes a nonlinear dynamic model of the heavy trucks to evaluate the influence of the various working conditions on the ride comfort and road friendliness of the heavy vehicles based on Matlab/Simulink software. The weighted root mean square (RMS) acceleration responses of the vertical driver’s seat, the cab’s pitch and roll angles, and the dynamic load coefficient (DLC) are chosen as objective functions. The influence of the vehicle velocity and loads on the different road surfaces are evaluated based on the standard ISO 2631-1. The results show that the vehicle’s ride comfort is clearly affected on the road surfaces of ISO level C and D at the range of the vehicle velocity. Especially, the vehicle’s ride comfort is very poor at the velocity of 10-30 m.s-1 on ISO level D. The road friendliness of the vehicle is greatly decreased in the condition of the half-loaded vehicle. Particularly the vertical dynamic wheel loads at 2nd axle strongly affect the road damage at the velocity of 10-30 m.s-1

    Towards Design of High Spin Metal-free Materials

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    In this paper, in order to explore high-spin carbon-based magnetic materials with strong ferromagnetic coupling, geometric structure, electronic structure and magnetic properties of alternating stacks of π\pi -radical-halogenated-hydrocarbons and diamagnetic molecules have been investigated based on density-functional theory with dispersion correction. These alternating stacks are predicted to avoid the typical antiferromagnetic spin-exchange of indentical face-to-face radicals via spin polarization of a diamagnetic molecule in between. Our results show that π\pi-radical-halogenated-hydrocarbons like perchlorophenalenyl (C13_{13}Cl9)_{9}) is strong ferromagnetic coupling if alternatingly stacked with aromatics like fluorinated coronene (C24_{24}F12)_{12}) or coronene (C24_{24}H12)_{12}), while fluorinated perinaphthenyl (C13_{13}F9)_{9}) and perinaphthenyl (C13_{13}H9)_{9}) are not an equally good choice. The role of ligand configuration in determining exchange coupling in stacks is discussed. These results would give some hints for designing new high-spin carbon-based ferromagnetic materials
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