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This article investigates the trajectory tracking control problem for wheeled mobile robot (WMR) subject to both velocity and torque constraints. Firstly, a more general model is established by considering the displacement between the centre of mass and the midpoint of the driving wheels of the WMR, based on which, a new bounded kinematic controller is proposed by combining the first-order filtering approach to keep the trajectory tracking error asymptotically stable. Then the dynamic controller is designed and the stability of the overall closed-loop system is proved by the Lyapunov stability theory and Barbalat's lemma. Some conditions are given to ensure that both the velocity constraints and torque constraints are satisfied. Finally, some numerical examples are given to show the effectiveness and advantages of the method proposed in this paper. [ABSTRACT FROM AUTHOR]

Kenya is China’s comprehensive strategic and cooperative partner. In recent years, under the common concern and guidance of the two heads of state, China-Kenya relations have entered the best period in history, with political mutual trust deepening and practical cooperation leading the way in China-Africa cooperation. Kenya is gradually building and developing its own oil storage and transportation infrastructures. Meanwhile, Chinese oil companies should seize the “Golden Twenty Years” of China-Africa cooperation, for jointly pursuing common development, facing challenges, and sharing opportunities; make progress in the oil and gas investment and cooperation; and participate in the oil and gas exploration and development throughout Kenya. By this means, it will not only ensure the stable supply of domestic oil and gas, but also inject strong impetus into Kenya’s development.

This article analyzes reform and amendment of petroleum tax policy in Russia to investigate instability of tax regime which is one of the main concerns for decision making in asset acquisition. Historical and recent amendments of upstream fiscal terms in Russia are reviewed and studied in an attempt to understand the trends of reform. Tax burden of four different cases is modeled with the change of tax policy to analyze the effect of tax incentives. The recent “tax maneuver” of transferring export duty to Mineral Extraction Tax (MET) is studied in detail to analyze effects to upstream, refinery, and customers. Net present values of three field cases under previous tax regime and new Added Income Tax (AIT) regime are comparatively studied with cashflow modeling. The article concludes that recent “tax maneuver” has indirect influence on upstream sector but may lead to upward pressure on retail. New AIT regime introduces a universal taxation system and requires less government intervention, which may reduce aboveground risk of unstable fiscal regime and boost international investment in Russia. Also, key suggestions are summarized for international investors who are interested in oil and gas asset in Russia.

This paper studies the non-fragile H ∞ filter design problem for a class of delayed semi-Markov jump systems with non-linear perturbation under event-triggered strategy. By applying the Lyapunov stability theory and matrix integral inequalities, sufficient conditions for the stochastic stability and H ∞ performance of the filtering error system are obtained. Then, a co-design method of the filter parameters and event-triggered matrices is developed. Finally, two simulation results are given to illustrate the usefulness of the proposed scheme. [ABSTRACT FROM AUTHOR]