Homotopy Continuation Method for Solving a Class of Slightly Perturbed Equations

In the present paper, an iterative method of second order convergence for solving a class of slightly perturbed equations is established using homotopy continuation technique. The accuracy of the method is very high and verified through two applications, in the first application we fix all the input parameters of our algorithm and allow the homotopy function to vary. For this application we considered as a typical example, Kepler equation of elliptical motion. In the second applications, the function is fixed while the other input parameters of the algorithm are varied, and we used for these applications seven highly transcendental slightly perturbed equations. The most important characteristic of the method is that it does not need any priori knowledge of the initial guess, a property which avoids the critical situations between divergent to very slow convergent solutions, that may exist in the application of other numerical methods which depending on initial guess. Moreover, the method allows freedom in choosing the function in order to secure any required accuracy

Investigation of all-wheel-drive off-road vehicle dynamics augmented by visco-lock devices

A peculiarity of AWD off-road vehicles is that their behaviour depends not only on the total power, provided by the engine, but also on its distribution among the drive axles/wheels. In turn, this distribution is largely regulated by the drivetrain layout and its torque distribution devices. At the output of the drivetrain system, the torque is constrained by the interaction between the wheels and the soft soil. For off-road automotive applications, the design of drivetrain systems has usually been largely dominated by the mobility requirements. With the growing demand to have a multipurpose on/off road vehicle with improved manoeuvrability over deformable soil, particularly at higher speed, the challenges confronting vehicle designers have become more complex. The thesis presents a novel integrated numerical approach to assess the dynamic behaviour of all-wheel-drive vehicles whilst operating over deformable soil terrain. [Continues.

Effect of non-Hermiticity on adiabatic elimination in coupled waveguides

We investigate the influence of non-Hermiticity on the adiabatic elimination in coupled waveguides.We show that although the total norm of the system is not conserved in parity-time symmetric phase, the dark state intensity remains constant. However, in broken phase the eliminated waveguide loses its darkness, i.e., its field amplitude starts increasing. In both exact and broken phases, the effective Hamiltonian derived from the adiabatic elimination condition describes the dynamics of all states except the dark state. Specifically, it cannot predict the amplification in the intensity of the dark state. Our results can strengthen the control of the dynamics in cavities with active elements and improve the design of controllable absorbers

Fiscal Transparency, Measurement and Determinants: Evidence from 27 Developing Countries

Fiscal transparency has been consistently identified as a key feature of efficient fiscal policy and a prerequisite for good public governance. However, measuring fiscal transparency remains an empirical challenge, and extant literature on developing countries is still sparse. To that end, this paper examines the determinants of fiscal transparency in developing countries. We add to the existing literature by proposing a new replicable index of fiscal transparency that is consistent with the definition provided by the International Monetary Fund (IMF) and the World Bank. Additional determinants of fiscal transparency, which are exclusively relevant in the study of developing countries, are also examined. In particular, we introduce such factors as natural resources, openness of the economy, the literacy rate of the population, and the quality of institutions. Because of possible endogeneity arising from interdependence among some variables, two-stage least squares (2SLS) is used to ensure that the estimators are consistent. As a robustness check, the same estimation procedure was replicated by replacing our index of fiscal transparency with respectively the index of Andreula et al. (2009) and the Open Budget Index, both of which use a significant similar number of developing countries of our selected sample. The results provide additional credence to our suggested procedure. The paper found that the level of natural resources and the openness of the capital account negatively affect fiscal transparency. However, the quality of institutions and literacy were found to positively affect fiscal transparency. The findings of this paper provide an explanation of why, after a decade of fiscal transparency programs, many developing countries are still lagging behind, thereby losing the potential benefits mentioned in the literature. These findings could help guide policies directed at improving fiscal transparency in the case of developing countries

Geochemical and biomarker characteristics of crude oils and source rock hydrocarbon extracts: An implication to their correlation, depositional environment and maturation in the Northern Western Desert, Egypt

AbstractOil–oil and oil–source rock correlations are used in this study in order to achieve their relationship, depositional environments and diagenetic processes in the source rocks. Three oil samples and source rock hydrocarbon extracts were analyzed using relative geochemical analyses, and gas chromatography–mass spectrometry are used for this purpose. The results revealed that the extracts of the Alam El Bueib and Khatatba formations are derived from mixed organic sources in which terrestrial dominates marine sources, and deposited in transitional environments under less anoxic conditions. The extracts of Bahariya formation are derived from mixed marine inputs with a limited terrestrial contribution. The Alam El Bueib oil shows more contribution of terrestrial than marine sources. Also, a genetic close relation between them supported the indigenous mixed source of Alam El Bueib oil which related to different sources including the Khatatba, Alam El Bueib and Bahariya formations. Accordingly, the Alam El Bueib formation can be considered as an important source for petroleum generation in the Northern Western Desert