Inter-CubeSat Communication with V-band "Bull's eye" antenna

We present the study of a simple communication scenario between two CubeSats using a V-band “Bull's eye” antenna that we designed for this purpose. The return loss of the antenna has a -10dB bandwidth of 0.7 GHz and a gain of 15.4dBi at 60 GHz. Moreover, the low-profile shape makes it easily integrable in a CubeSat chassis. The communication scenario study shows that, using 0.01W VubiQ modules and V-band “Bull’s eye” antennas, CubeSats can efficiently transmit data within a 500 MHz bandwidth and with a 10-6 BER while being separated by up to 98m, under ideal conditions, or 50m under worst case operating conditions (5° pointing misalignment in E- and H-plane of the antenna, and 5° polarisation misalignment)

Allatostatin-A neurons inhibit feeding behavior in adult Drosophila

How the brain translates changes in internal metabolic state or perceived food quality into alterations in feeding behavior remains poorly understood. Studies in Drosophila larvae have yielded information about neuropeptides and circuits that promote feeding, but a peptidergic neuron subset whose activation inhibits feeding in adult flies, without promoting metabolic changes that mimic the state of satiety, has not been identified. Using genetically based manipulations of neuronal activity, we show that activation of neurons (or neuroendocrine cells) expressing the neuropeptide allatostatin A (AstA) inhibits or limits several starvation-induced changes in feeding behavior in adult Drosophila, including increased food intake and enhanced behavioral responsiveness to sugar. Importantly, these effects on feeding behavior are observed in the absence of any measurable effects on metabolism or energy reserves, suggesting that AstA neuron activation is likely a consequence, not a cause, of metabolic changes that induce the state of satiety. These data suggest that activation of AstA-expressing neurons promotes food aversion and/or exerts an inhibitory influence on the motivation to feed and implicate these neurons and their associated circuitry in the mechanisms that translate the state of satiety into alterations in feeding behavior

Mapless Online Detection of Dynamic Objects in 3D Lidar

This paper presents a model-free, setting-independent method for online detection of dynamic objects in 3D lidar data. We explicitly compensate for the moving-while-scanning operation (motion distortion) of present-day 3D spinning lidar sensors. Our detection method uses a motion-compensated freespace querying algorithm and classifies between dynamic (currently moving) and static (currently stationary) labels at the point level. For a quantitative analysis, we establish a benchmark with motion-distorted lidar data using CARLA, an open-source simulator for autonomous driving research. We also provide a qualitative analysis with real data using a Velodyne HDL-64E in driving scenarios. Compared to existing 3D lidar methods that are model-free, our method is unique because of its setting independence and compensation for pointcloud motion distortion.Comment: 7 pages, 8 figure

Earthshine as an Illumination Source at the Moon

Earthshine is the dominant source of natural illumination on the surface of the Moon during lunar night, and at locations within permanently shadowed regions that never receive direct sunlight. As such, earthshine may enable the exploration of areas of the Moon that are hidden from solar illumination. The heat flux from earthshine may also influence the transport and cold trapping of volatiles present in the very coldest areas. In this study, Earth's spectral radiance at the Moon is examined using a suite of Earth spectral models created using the Virtual Planetary Laboratory (VPL) three dimensional modeling capability. At the Moon, the broadband, hemispherical irradiance from Earth near 0 phase is approximately 0.15 watts per square meter, with comparable contributions from solar reflectance and thermal emission. Over the simulation timeframe, spanning two lunations, Earth's thermal irradiance changes less than a few mW per square meter as a result of cloud variability and the south-to-north motion of sub-observer position. In solar band, Earth's diurnally averaged light curve at phase angles < 60 degrees is well fit using a Henyey Greenstein integral phase function. At wavelengths > 0.7 microns, near the well known vegetation "red edge", Earth's reflected solar radiance shows significant diurnal modulation as a result of the longitudinal asymmetry in projected landmass, as well as from the distribution of clouds. A simple formulation with adjustable coefficients is presented for estimating Earth's hemispherical irradiance at the Moon as a function of wavelength, phase angle and sub-observer coordinates. It is demonstrated that earthshine is sufficiently bright to serve as a natural illumination source for optical measurements from the lunar surface.Comment: 27 pages, 15 figures, 1 tabl

Learning policies through argumentation-derived evidence (extended abstract)

(c) IFAAMASPublisher PD

The executive toolbox:building legislative support in a multiparty presidential regime

How do presidents win legislative support under conditions of extreme multipartism?Comparative presidential research has offered two parallel answers, one relying on distributivepolitics and the other claiming that legislative success is a function of coalition formation. Wemerge these insights in an integrated approach to executive-legislative relations, also addingcontextual factors related to dynamism and bargaining conditions. We find that the twopresidential “tools” – pork and coalition goods – are substitutable resources, with porkfunctioning as a fine-tuning instrument that interacts reciprocally with legislative support. Porkexpenditures also depend upon a president’s bargaining leverage and the distribution oflegislative seats.

An Access Control Model for Protecting Provenance Graphs

Postprin