The effect of aggregate foreign direct investment (FDI) on economic growth remains uncertain in the literature. We revisit this FDI-Growth relation by analyzing the components of FDI - greenfield investment and cross-border mergers and acquisitions (M&As). Our analysis contributes to the existing literature by focusing on potentially heterogeneous growth effects of different FDI entry modes. Using a sample of 84 countries from 1987 to 2001, we separately examine the growth effects of greenfield investment and M&As. We find that greenfield investment and M&As have different impacts on economic growth. Greenfield investment promotes economic growth while M&As can be beneficial only when the host country has an adequate level of human capital. Our results provide support for receiving M&As when policymakers allocate more resources for human capital accumulation. Copyright 2009 Blackwell Publishing Ltd.

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A comprehensive mathematical model of a typical hydraulic power steering system equipped with variable ratio rack and pinion gear is developed. The steering system's dynamic characteristics are investigated and its forced vibrations are compared with those obtained from a counterpart system with a constant ratio rack and pinion gear. The modeling details of the mechanism subsystem, hydraulic supply lines subsystem and the rotary spool valve subsystem are provided and included in the integrated steering system model. The numerical simulations are conducted to investigate the dynamics of the nonlinear parametric steering system. From the comparison between simulated results and the experimental ones, it is shown that the model accurately integrates the boost characteristics of the rotary spool valve which is the key component of hydraulic power steering system. The variable ratio rack-pinion gear behaviors significantly differently from its constant ratio counterpart does. It significantly affects not only the system natural frequencies but also reduces vibrations under constant rate and ramp torque steering inputs. The developed steering model produces valid predictions of the system's behavior and therfore could assist engineers in the design and analysis of integrated steering systems.

The integrated modular avionics (IMA) system is widely used in all classes of aircraft as a result of its high functional integration and resource utilization in developing advanced avionics systems. However, a series of challenges related to safety assessment exist in the background of the logical architecture for multi-message interactions of the IMA system. Traditional safety assessment methods are mainly based on engineering experience, and are difficult to reuse, incomplete, and even error-prone. Here we propose a method to assess the availability of the IMA system based on the thinking of model-based safety analysis. To aid the proposed method, we implement a tool to generate a AltaRica 3.0 file used to assess the IMA system model. The simulation results show that the proposed method makes the availability assessment fast, efficient, and effective. Moreover, we apply this method to the modification analysis of the IMA system under the condition of satisfying the safety requirement. Our study can enhance the safety assessment of safety-critical systems effectively, assist the design of IMA systems, and reduce the amount of errors during the programming process of the safety model.

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