Obstacle problem for Arithmetic Asian options

We prove existence, regularity and a Feynman-Ka\v{c} representation formula of the strong solution to the free boundary problem arising in the financial problem of the pricing of the American Asian option with arithmetic average

Information Spreading in Stationary Markovian Evolving Graphs

Markovian evolving graphs are dynamic-graph models where the links among a fixed set of nodes change during time according to an arbitrary Markovian rule. They are extremely general and they can well describe important dynamic-network scenarios. We study the speed of information spreading in the "stationary phase" by analyzing the completion time of the "flooding mechanism". We prove a general theorem that establishes an upper bound on flooding time in any stationary Markovian evolving graph in terms of its node-expansion properties. We apply our theorem in two natural and relevant cases of such dynamic graphs. "Geometric Markovian evolving graphs" where the Markovian behaviour is yielded by "n" mobile radio stations, with fixed transmission radius, that perform independent random walks over a square region of the plane. "Edge-Markovian evolving graphs" where the probability of existence of any edge at time "t" depends on the existence (or not) of the same edge at time "t-1". In both cases, the obtained upper bounds hold "with high probability" and they are nearly tight. In fact, they turn out to be tight for a large range of the values of the input parameters. As for geometric Markovian evolving graphs, our result represents the first analytical upper bound for flooding time on a class of concrete mobile networks.Comment: 16 page

Identification of C-band radio frequency interferences from Sentinel-1 data

We propose the use of Sentinel-1 Synthetic Aperture Radar (SAR) to provide a continuous and global monitoring of Radio Frequency Interferences (RFI) in C-band. We take advantage of the first 8-10 echo measures at the beginning of each burst, a 50-70 MHz wide bandwidth and a ground beam coverage of ~25 km (azimuth) by 70 km (range). Such observations can be repeated with a frequency better than three days, by considering two satellites and both ascending and descending passes. These measures can be used to qualify the same Sentinel-1 (S1) dataset as well as to monitor the availability and the use of radio frequency spectrum for present and future spaceborne imagers and for policy makers. In the paper we investigate the feasibility and the limits of this approach, and we provide a first Radio Frequency Interference (RFI) map with continental coverage over Europe

Assessing the impact of the ECB's Corporate Sector Purchase Programme on SMEs

The European Central Bank's Governing Council is due to hold a policy meeting on 26 October, with many observers anticipating there could be a change to the ECB's monetary stimulus programme. Corrado Macchiarelli, Mara Monti and Andrea Vedolin examine some of the measures that should be considered as the ECB looks to respond to changing conditions in the euro area

The bio-based economy can serve as the springboard for camelina and crambe to quit the limbo

Social, economic and environmental importance of bio-based economy is rapidly growing and vegetable oils play an important role. About 75% of global production of vegetable oils derives from commodity oilseeds (i.e., soybean, oil palm, rapeseed), while the remaining 25% is produced from minor oilseeds characterized by unusual fatty acid composition. The present review aims at analyzing the potentialities of two alternative oilseed crops for Europe, camelina (Camelina sativa) and crambe (Crambe abyssinica), identified as major candidates for the future European bio-based economy as testified by the recently funded EU Project (Horizon 2020) COSMOS (Camelina and crambe Oilcrops as Sources of Medium-chain Oils for Specialty oleochemicals). The interest on camelina and crambe is mainly due to their unique fatty acid profile, low input management and wide environmental adaptability. We attempted to analyze pros and cons of development of camelina and crambe in Europe in the light of biorefinery concept (i.e.,using oil and whole produced biomass) as undertaken by COSMOS project

Internal conductance under different light conditions along the plant profile of Ethiopian mustard (Brassica carinata A. Brown.)

This study focused on the internal conductance (g i ) along the plant profile of Ethiopian mustard under two light conditions: (i) light from the top only (I1); (ii) light from the top integrated by supplementary lateral light along the whole plant profile (I2). Lateral light strongly increased the productivity (e.g. +104% of seed oil) and net photosynthesis (A). The latter appeared more driven by g i (r=0.78 ** ) than by stomatal conductance (g s ) (r=0.51 * ). Importantly, irradiance also considerably shortened the time from leaf appearance to senescence, which means that corresponding leaves in I1 and I2 had different ages. Therefore, since leaf age and irradiance have counteracting effects on g i , I1 sometimes showed higher g i values than I2. With respect to irradiance, leaf age had clearly higher effects on g i , which radically declined from the top to the basal leaves, even under constant light conditions. The internal conductance caused a significant drawdown of CO 2 from the sub-stomatal cavity (C i ) to the site of carboxylation (C c ) that, in turn, led to a substantial underestimation of V cmax calculated using the A/C i model. Again, the trends of g i and g s were not consistent along the plant profile, and so the ratio between stomatal and internal limitations to A changed from top to bottom leaves, accordingly. This study suggests that g i may be a valuable trait for increasing photosynthetic capacity and productivity; nonetheless, it suggests caution in selecting leaves for high g i , as the latter can considerably change along the plant profile due to leaf age and irradiance effects

Impact of scene decorrelation on geosynchronous SAR data focusing

We discuss the effects of the clutter on geosynchronous SAR systems exploiting long integration times (from minutes to hours) to counteract for two-way propagation losses and increase azimuth resolution. Only stable targets will be correctly focused whereas unstable targets will spread their energy along azimuth direction. We derive here a generic model for the spreading of the clutter energy based on the power spectral density of the clutter itself. We then assume the Billingsley Intrinsic Clutter Motion model, representing the clutter power spectrum as an exponential decay, and derive the expected GEOSAR signal-to-clutter ratio. We also provide some results from a Ground Based RADAR experiment aimed at assessing the long-term clutter statistics for different scenarios to complement the Internal Clutter Motion model, mainly derived for windblown trees. Finally, we discuss the expected performances of two GEOSAR systems with different acquisition geometries.Peer ReviewedPostprint (published version