15 research outputs found

    Comparison of accelerating ion populations observed upstream of the bow shocks at Venus and Mars

    No full text
    Foreshock ions are compared between Venus and Mars at energies of 0.6~20 keV using the same ion instrument, the Ion Mass Analyser, on board both Venus Express and Mars Express. Venus Express often observes accelerated protons (2~6 times the solar wind energy) that travel away from the Venus bow shock when the spacecraft location is magnetically connected to the bow shock. The observed ions have a large field-aligned velocity compared to the perpendicular velocity in the solar wind frame, and are similar to the field-aligned beams and intermediate gyrating component of the foreshock ions in the terrestrial upstream region. Mars Express does not observe similar foreshock ions as does Venus Express, indicating that the Martian foreshock does not possess the intermediate gyrating component in the upstream region on the dayside of the planet. Instead, two types of gyrating protons in the solar wind frame are observed very close to the Martian quasi-perpendicular bow shock within a proton gyroradius distance. The first type is observed only within the region which is about 400 km from the bow shock and flows tailward nearly along the bow shock with a similar velocity as the solar wind. The second type is observed up to about 700 km from the bow shock and has a bundled structure in the energy domain. A traversal on 12 July 2005, in which the energy-bunching came from bundling in the magnetic field direction, is further examined. The observed velocities of the latter population are consistent with multiple specular reflections of the solar wind at the bow shock, and the ions after the second reflection have a field-aligned velocity larger than that of the de Hoffman-Teller velocity frame, i.e., their guiding center has moved toward interplanetary space out from the bow shock. To account for the observed peculiarity of the Martian upstream region, finite gyroradius effects of the solar wind protons compared to the radius of the bow shock curvature and effects of cold ion abundance in the bow shock are discussed

    Wages, productivity, and retirement

    No full text
    Retirement, Pension, Mandatory retirement, Wage compression, Efficient retirement, Firmspecific human capital, Life cycle earnings, Insurance model, Leisure, Pension benefits, Retirement age, Pay compression, Pension structure, M5,

    Managerial meta-knowledge and adaptation: Governance choice when firms don’t know their capabilities

    No full text
    How well do managers know the capabilities of the firms they manage? Such knowledge, which we refer to as managerial meta-knowledge, has not been systematically addressed in the management and governance literature—which is problematic, as managerial meta-knowledge influences governance choice. In fact, transaction cost economics, the dominant theory of governance choice in management research, assumes that managers perfectly know the capabilities of their firms. However, micro-level research streams on resource cognition and transactive memory, as well as the knowledge-based view of strategy, suggest that this assumption is not in general warranted: Managers’ meta-knowledge is in general imperfect. We therefore examine the implications of imperfect managerial meta-knowledge for governance choice. The key mechanism we highlight is that imperfect managerial meta-knowledge leads to surprises and frictions in contractual relationships, negatively influences the ability to engage in coordinated adaptation, and is a driver of ex post transaction costs. For these reasons, managerial meta-knowledge holds implications for governance choices, which we summarize in four propositions
    corecore