3,239 research outputs found

    Mars Atmospheric Entry Integrated Navigation with Partial Intermittent Measurements

    Get PDF
    Signal degradation suffered by the vehicle is a combination brownout and blackout during Mars atmospheric entry. The communications brownout means that signal fades and blackout means that the signal is lost completely. The communications brownout and blackout periods are analyzed and predicted with an altitude and velocity profiles. In the brownout period, the range measurements between the vehicle and the orbiters are modeled as intermittent measurements with the radio signal arrival probabilities, which are distributed as a Rayleigh distribution of the electron number density around the entry vehicle. A new integrated navigation strategy during the Mars atmospheric entry phase is proposed to consider the probabilities of the radio measurements in the communications brownout and blackout periods under the IMU/beacon scenario based on the information filter with intermittent measurements. Numerical navigation simulations are designed to show the performance of the proposed navigation strategy under the integrated navigation scenario

    A Review of the Eighth Forum of the World Association for Political Economy

    Get PDF
    There are many kinds of inequalities such as inequalities between nations, gender inequalities, racial inequalities, and especially income and wealth inequalities, which are emerging as the most important ones in the current global crisis of capitalism. Also, the latest historic crisis of capitalism has led to a decline in the levels of growth in the world, especially in Europe, with enormous social consequences. The response of the dominant classes in these countries to these problems has been the imposition of austerity policies. These policies instead of reducing unemployment and improving living standards have increased the reach of private capitalist activities. In May of 2013, WAPE held its Eighth Forum themed “Inequalities and World Capitalism: Analysis, Policy and Action.” The aim is to analyze the reasons for world inequality and counter measures against it, find the conditions of the world development from the radical perspective through renewed study of the finished and unfinished writings of Marx and of the plural realities of our time

    Observation of peripheral refraction in myopic anisometropia in young adults

    Get PDF
    AIM: To investigate the differences in retinal refraction difference values (RDVs) of adult patients with myopic anisometropia compared with those without myopic anisometropia, and to investigate the relationship between ocular biometric measurements and relative peripheral refraction. METHODS: This clinical observation study included 130 patients with myopia (-0.25 to -10.00 D) between October 2022 and January 2023 aged between 18 and 40y. The patients were divided into anisometropia (n=63; difference in binocular anisometropia ≥1.00 D) and non-anisometropia (n=67; difference in binocular anisometropia 0.05). There was a negative correlation between SE and TRDV (r=-0.205, P=0.001), RDV-20-53 (r=-0.281, -0.183, -0.176, P<0.05), RDV-superior (r=-0.251, P<0.001), and RDV-temporal (r=-0.230, P<0.001), a negative correlation between CYL and RDV-10-30 (r=-0.147, -0.180, P<0.05), and a negative correlation between SRI and RDV-0-20 (r=-0.190, -0.170, P<0.05). AL had a positive correlation with RDV-20-30 (r=0.164, P=0.008) and RDV-temporal (r=0.160, P=0.010). CONCLUSION: More myopic eyes in patients with myopic anisometropia show more peripheral hyperopic defocus. Diopter and corneal morphology may affect peripheral retinal defocus
    corecore