Approximately optimal trade execution strategies under fast mean-reversion

In a fixed time horizon, appropriately executing a large amount of a particular asset -- meaning a considerable portion of the volume traded within this frame -- is challenging. Especially for illiquid or even highly liquid but also highly volatile ones, the role of "market quality" is quite relevant in properly designing execution strategies. Here, we model it by considering uncertain volatility and liquidity; hence, moments of high or low price impact and risk vary randomly throughout the trading period. We work under the central assumption: although there are these uncertain variations, we assume they occur in a fast mean-reverting fashion. We thus employ singular perturbation arguments to study approximations to the optimal strategies in this framework. By using high-frequency data, we provide estimation methods for our model in face of microstructure noise, as well as numerically assess all of our results

Allineamento in volo tra SuperAGILE e gli star-tracker

We report the quaternions obtained to align the star trackers to the SuperAGILE line of sight with less than 1 arcmin precisio

Andamento delle soglie di SuperAGILE con la temperatura nella fase di volo dell'esperimento

We analyse flight data of SuperAGILE imager, and found the variation of the energy threshold of each ASIC with temperature. We discuss that the onboard energy threshold should be changed with pointing, because the temperature of the imager varies with the pointing of the satellit

Analisi delle acquisizioni di laboratorio e delle simulazioni in vista delle calibrazioni di SuperAGILE con sorgenti a distanza finita

We analyse data from the SuperAGILE WFM taken with a radioactive source at finite distance, we compare results with the simulation, and we evaluate the radioactive sources and integration time needed for the ground calibrations of the angular response of the imager

TRANSCONSTITUCIONALISMO: UM PASSO PARA UMA CONSTITUIÇÃO GLOBAL

Analisando as conjunturas de relações interpessoais, e em uma perspectiva macro, Inter Estados, ou as relações jurídicas Estado-cidadão, é de fácil constatação o início da influência exercida pela globalização nos mais diversos segmentos, ditando, por diversas vezes, o andamento e a resolução de possíveis conflitos a níveis nacionais e internacionais. Levando em consideração que a maior parte dos vínculos que podemos identificar como significativamente relevantes podem apresentar, também, consideráveis consequências, é importante observar que estas, provavelmente, terão repercussão extranacional, podendo abranger faticamente países diferentes, com ordenamentos jurídicos distintos, e com posições diversas a respeito de mesmo fato. Portanto, busca-se agregar a essa consequência natural do crescimento econômico, uma maior gama de precedentes jurídicos, a qual pode ser estabelecida tanto através do diálogo entre cortes de distintas localidades e hierarquia, como mediante junção de textos constitucionais diversos, a fim de regulamentar com maior segurança jurídica, e em conformidade com princípios e garantias fundamentais, para objetivar a melhor condição de vida do homem pós moderno

Calibrating the IXPE Observatory from Ground to Space

The Imaging X-ray Polarimetry Explorer (IXPE) will be the next SMEX mission launched by NASA in 2021 in collaboration with the Italian Space Agency (ASI). IXPE will perform groundbreaking measurements of imaging polarization in X-rays for a number of different classes of sources with three identical telescopes, finally (re)opening a window in the high energy Universe after more than 40 years since the first pioneering results. The unprecedented sensitivity of IXPE to polarization poses peculiar requirements on the payload calibration, e.g. the use of polarized and completely unpolarized radiation, both on ground and in orbit, and can not rely on a systematic comparison with results obtained by previous observatories. In this paper, we will present the IXPE calibration plan, describing both calibrations which will be performed on the detectors at INAF-IAPS in Rome (Italy) and the calibration on the mirror and detector assemblies which will be carried out at Marshall Space Flight Center in Huntsville, Alabama. On orbit calibrations, performed with calibrations sources mounted on a filter wheel and placed in front of each detector when necessary, will be presented as well

Characterization of the NNVT capillary plate collimators

In this paper, we report the results of the characterization campaign of two prototypes of Micro-Channel Plates (MCPs), designed as the X-ray collimators for the Large Area Detector on board the eXTP mission. The devices were developed ad-hoc by North Night Vision Technology Co., Ltd. (Nanjing, China). Measurements involved the study of the angular response (rocking curve) of each device to X-rays of different energies. The study evidenced how the angular response of a collimator changes with the energy of the incoming photons, with the onset of side lobes at high energy, which enlarge the effective field of view of the device, causing a potential contamination of the on-axis signal. Nevertheless, the magnitude of this effect is proven to be acceptable in most situations of astrophysical interest. On the lower hand of the energy spectrum, photons may also modify the angular response due to grazing reflection on the inner walls of the collimator, a phenomenon strongly dependent on the degree of roughness of the surfaces involved. The whole campaign took place at the INAF/IAPS laboratories in Rome