Realized Correlation Tick-by-Tick

We propose the Heterogeneous Autoregressive (HAR) model for the estimation and prediction of realized correlations. We construct a realized correlation measure where both the volatilities and the covariances are computed from tick-by-tick data. As for the realized volatility, the presence of market microstructure can induce significant bias in standard realized covariance measure computed with artificially regularly spaced returns. Contrary to these standard approaches we analyse a simple and unbiased realized covariance estimator that does not resort to the construction of a regular grid, but directly and efficiently employs the raw tick-by-tick returns of the two series. Montecarlo simulations calibrated on realistic market microstructure conditions show that this simple tick-by-tick covariance possesses no bias and the smallest dispersion among the covariance estimators considered in the study. In an empirical analysis on S&P 500 and US bond data we find that realized correlations show significant regime changes in reaction to financial crises. Such regimes must be taken into account to get reliable estimates and forecasts.High frequency data, Realized Correlation, Market Microstructure, Bias correction, HAR, Regimes

Bond Risk Premia Forecasting: A Simple Approach for Extracting¨Macroeconomic Information from a Panel of Indicators

We propose a simple but effective estimation procedure to extract the level and the volatility dynamics of a latent macroeconomic factor from a panel of observable indicators. Our approach is based on a multivariate conditionally heteroskedastic exact factor model that can take into account the heteroskedasticity feature shown by most macroeconomic variables and relies on an iterated Kalman filter procedure. In simulations we show the unbiasedness of the proposed estimator and its superiority to different approaches introduced in the literature. Simulation results are confirmed in applications to real inflation data with the goal of forecasting long-term bond risk premia. Moreover, we find that the extracted level and conditional variance of the latent factor for inflation are strongly related to NBER business cycles.Macroeconomic variables; Exact factor model; Kalman filter; Heteroskedasticity; Forecasting bond risk premia; Inflation measures; Business cycles

Bilanci di filiera per la produzione di metano da biomasse

Si sono sviluppati bilanci delle filiere di produzione di biometano a partire da pioppo e microalghe. Si sono analizzate le tecniche di coltivazione e raccolta delle biomasse. Si è analizzata la conversione della biomassa a syngas e biogas, studiando la gassificazione del cippato di pioppo e la digestione anaerobica delle microalghe Chlorella Vulgaris e Nannochloropsis Gaditana. Si sono poi analizzati i processi di upgrading per l'ottenimento di biometano. Infine sono stati fatti i confronti fra le filiere sulla base dei consumi di fertilizznti, di energia elettrica e termica e in merito alle emissioni di CO2

Bond Risk Premia Forecasting: A Simple Approach for Extracting Macroeconomic Information from a Panel of Indicators

We propose a simple but effective estimation procedure to extract the level and the volatility dynamics of a latent macroeconomic factor from a panel of observable indicators. Our approach is based on a multivariate conditionally heteroskedastic exact factor model that can take into account the heteroskedasticity feature shown by most macroeconomic variables and relies on an iterated Kalman filter procedure. In simulations we show the unbiasedness of the proposed estimator and its superiority to different approaches introduced in the literature. Simulation results are confirmed in applications to real inflation data with the goal of forecasting long-term bond risk premia. Moreover, we find that the extracted level and conditional variance of the latent factor for inflation are strongly related to NBER business cycles

A SMART PASSIVE YAW DAMPER FOR THE REDUCTION OF LATERAL CONTACT FORCES IN LOW-RADIUS CURVED TRACKS

High-speed trains are equipped with yaw dampers to prevent the arising of hunting motion. These suspension components play an important role in improving the vehicle stability. However, the presence of yaw dampers increases the steering resistance of the bogies, especially in transient curve track segments. For this reason, passive yaw dampers are designed according to a tradeoff between improvement of high-speed stability and limitation of curving performance degradation. This paper introduces an innovative passive smart yaw damper, the Position Dependent Yaw Damper, able to overcome the typical limitations of standard passive components. The damper can variate its dynamic performances according to the operating conditions of the vehicle. In this paper, a PDYD prototype will be experimentally characterized. Then, a numerical model of the damper will be tuned on the experimental data. The model aims at predicting the influence of the PDYD on the dynamic performances of a rail vehicle, simulated with a Multibody model. A sensitivity analysis will assess the relationship between different PDYD layouts and the vehicle curving performances co-simulating damper and vehicle models. The numerical comparison will be focused on the low-speed negotiation of low radius curves. Finally, the best PDYD layout will be implemented in a numerical simulation of a high-speed high-radius curve to verify its effectiveness in reducing the arising of hunting unstable motion

Adult-type rhabdomyoma of the larynx: clinicopathologic study of an uncommon tumor in a rare location

Rhabdomyoma is an uncommon benign mesenchymal tumor with skeletal muscle differentiation that may occur either in the heart or in extra-cardiac sites. Even though the head and neck region is the most common area of extra-cardiac rhabdomyoma, the larynx is rarely involved. We present the case of an 85-year-old woman who reported a 10-day history of breathing difficulties, dysphagia and dysphonia. A computed tomography scan of the head and neck showed a contrast-enhanced, solid hypopharyngeal-laryngeal neoplasm with well-defined margins causing subtotal obliteration of the right pyriform sinus and a reduction in air lumen of the laryngeal vestibule. The patient underwent complete endoscopic removal of the lesion; histologic examination revealed an adult- type rhabdomyoma based on the histologic features and the immunoreactivity of the neoplastic cells for desmin, myoglobin and muscle-specific actin but not for cytokeratin, S-100, CD68R, chromogranin-A and synaptophysin. Since clinical and imaging features are not specific for rhabdomyoma, histologic examination and immunohistochemical analyses play a central role in the differential diagnosis of the adult-type rhabdomyoma from other laryngeal neoplasms. A correct diagnosis is mandatory to avoid inappropriate treatment

ASIC development for SiPM readout

The design of CMOS front-end electronics suitable for Silicon Photo-Multipliers (SiPM) is described in this paper, starting with the specification of an accurate electrical model of the detector and its experimental validation. A novel current-mode solution is proposed for the preamplifier and the discriminator, to cope with the large dynamic range and the extremely fast rise time of the detector signal. Experimental results achieved from front-end prototypes designed according to this current-mode approach demonstrate its effectiveness: dynamic range of the order of 50 pC and timing accuracy of the electronics alone of about 30 ps have been measured

Robotic total gastrectomy with intracorporeal robot-sewn anastomosis. A novel approach adopting the double-loop reconstruction method

Gastric cancer constitutes a major health problem. Robotic surgery has been progressively developed in this field. Although the feasibility of robotic procedures has been demonstrated, there are unresolved aspects being debated, including the reproducibility of intracorporeal in place of extracorporeal anastomosis. Difficulties of traditional laparoscopy have been described and there are well-known advantages of robotic systems, but few articles in literature describe a full robotic execution of the reconstructive phase while others do not give a thorough explanation how this phase was run. A new reconstructive approach, not yet described in literature, was recently adopted at our Center. Robotic total gastrectomy with D2 lymphadenectomy and a socalled ‘‘double-loop’’ reconstruction method with intracorporeal robotsewn anastomosis (Parisi’s technique) was performed in all reported cases. Preoperative, intraoperative, and postoperative data were collected and a technical note was documented. All tumors were located at the upper third of the stomach, and no conversions or intraoperative complications occurred. Histopathological analysis showed R0 resection obtained in all specimens. Hospital stay was regular in all patients and discharge was recommended starting from the 4th postoperative day. No major postoperative complications or reoperations occurred. Reconstruction of the digestive tract after total gastrectomy is one of the main areas of surgical research in the treatment of gastric cancer and in the field of minimally invasive surgery. The double-loop method is a valid simplification of the traditional technique of construction of the Roux-limb that could increase the feasibility and safety in performing a full hand-sewn intracorporeal reconstruction and it appears to fit the characteristics of the robotic system thus obtaining excellent postoperative clinical outcome