MUSTACHE: Multi-Step-Ahead Predictions for Cache Eviction

In this work, we propose MUSTACHE, a new page cache replacement algorithm whose logic is learned from observed memory access requests rather than fixed like existing policies. We formulate the page request prediction problem as a categorical time series forecasting task. Then, our method queries the learned page request forecaster to obtain the next $k$ predicted page memory references to better approximate the optimal B\'el\'ady's replacement algorithm. We implement several forecasting techniques using advanced deep learning architectures and integrate the best-performing one into an existing open-source cache simulator. Experiments run on benchmark datasets show that MUSTACHE outperforms the best page replacement heuristic (i.e., exact LRU), improving the cache hit ratio by 1.9% and reducing the number of reads/writes required to handle cache misses by 18.4% and 10.3%

aeroelastic investigation of a transonic compressor rotor with multi row effects

Abstract According to the modern turbomachinery design trend, blades are getting more and more flexible and loaded, and therefore prone to vibration issues due to forced response and flutter phenomena. For this reason, the flutter stability assessment has become a key aspect to avoid high cycle fatigue (HCF) blade failures. The aim of this paper is to numerically evaluate the influence of unsteady aerodynamic effects, due to upstream and downstream rows, on flutter predictions using an uncoupled method. Both CFD aeroelastic and modal analyses have been carried out for a one and half compressor stage in transonic conditions. Flutter results are reported for the classic single-row approach and then for the multi-row model which includes rotor/stator unsteady interactions: a good agreement with measured data is shown for both cases and also a no negligible impact of adjacent rows can be observed

numerical study of flutter stabilization in low pressure turbine rotor with intentional mistuning

Abstract Intentional mistuning concepts are used to mitigate the risk of flutter occurrence for compressor and turbine blades, as this design strategy represents one of the key aspects in nowadays turbomachinery aeroelastic design. In this paper, the effects of a mistuning pattern on LPT flutter stability are numerically investigated in order to highlight the differences with the classic tuned configuration. A LPT rotor is analysed with an intentional mistuning pattern composed by alternate blades with different additional masses at the blade tip, and the corresponding tuned configuration, consisting of the blisk (blade+disk) with identical blades. The first part of this work is devoted to the modal analysis for tuned and mistuned cases. Frequencies and mode shapes of the first bending mode family, obtained by FEM modal analysis in cyclic symmetry, are then used to perform CFD flutter analysis with moving blades. The results confirm the stabilizing effect of alternate mistuning pattern in contrast with the tuned system which denotes a strong flutter instability for a large range of negative nodal diameters. The numerically predicted flutter stabilization effect has been confirmed by measurements carried out during a tip timing experimental campaign performed within the Future EU project

Empathy and perceived burden in caregivers of patients with schizophrenia spectrum disorders

Background Caregivers of patients load different kinds of burdens, including emotional distress. Aims of this study were to evaluate both burden and empathy of caregivers who assist patients with schizophrenia spectrum disorders. Methods We selected a sample of 60 caregivers (34 women and 26 men), who assisted patients with schizophrenia spectrum disorders treated in our local Community Mental Health Center for a 1-year minimum period. We administered two scales to our sample, Zarit Burden Interview (ZBI) and Balanced Emotional Empathy Scale (BEES), and collected data of caregivers and their assisted patients in a 3-month period. Data were statistically analyzed. Results We reported a mean ZBI score of 49.68 (±15.03 SD) and a mean BEES score of 14.35 (±9.05 SD), indicating the perception of moderate-severe burden and low level of empathy, respectively. The analysis of internal consistency confirmed the good reliability of both ZBI (Cronbach’s alpha = 0.90) and BEES (Cronbach’s alpha = 0.77). The correlation between the two scales was not statistically significant at Spearman test. At our multiple linear regression, many variables of both caregiver and patient showed a significant correlation with the ZBI score. In particular, not living with the assisted patient and female gender of caregiver potentially decreased the burden, whereas clinical severity of assisted patient and two caregiver conditions, middle school education and spouse relationship with patient, could worsen the burden. We highlighted two positive statistically significant correlations between the total score of BEES and caregiver characteristics: being spouse and not living with assisted patient. Conclusions Our study highlights that the caregiver burden of patients with severe psychiatric disorders is high and is associated with low emotional empathy experienced by caregivers, probably due to a defensive psychological mechanism. The conditions of spouse and cohabitation can concomitantly increase both empathy and burden in caregivers

Tableros para aulas de plástica

El proyecto está orientado a cubrir la necesidad de equipar aulas para los alumnos de la carrera de Plástica de la FBA. La solicitud del Departamento de Plástica contenía tres condiciones de uso: que se pudiera trabajar sobre el tablero en posición horizontal y en posición vertical y, en esta misma posición, que sirviera como soporte para las exposiciones. (Párrafo extraído del texto a modo de resumen)Facultad de Bellas Arte

Allaboard a system for exploring urban mobility and optimizing public transport using cellphone data

The deep penetration of mobile phones offers cities the ability to opportunistically monitor citizens interactions and use data-driven insights to better plan and manage services. In this context, transit operators can leverage pervasive mobile sensing to better match observed demand for travel with their service offerings. With large scale data on mobility patterns, operators can move away from the costly and resource intensive transportation planning processes prevalent in the West, to a more data-centric view, that places the instrumented user at the center of development. In this framework, using mobile phone data to perform transit analysis and optimization represents a new frontier with significant societal impact, especially in developing countries. Document type: Part of book or chapter of boo

The Impact of COVID-19 Pandemic on Psychiatric Emergencies in Two Different Settings: Emergency Room and Community Mental Health Service

Background: The SARS-CoV-2 pandemic caused a public health emergency with profound consequences on the physical and mental health of individuals. Emergency Rooms (ER) and Community Mental Health Services (CMHS) played a key role in the management of psychiatric emergencies during the pandemic. The purpose of the study was to evaluate urgent psychiatric consultations (UPCs) in the ERs of the General Hospitals and in the CMHS of a Northern Italian town during the pandemic period. Methods: This monocentric observational study collected UPCs carried out in ER from 01/03/2020 to 28/02/2021 (the so-called “COVID-19 period”) and the demographic and clinical characteristics of patients who required UPCs in the 12-months period, comparing these data with those collected from 01/03/2019 to 29/02/2020 (the so-called “pre-COVID-19 period”). The same variables were collected for UPCs carried out in CMHS from 01/03/2020 to 31/01/2021 and compared with those collected from 01/03/2019 to 31/01/2020. The data were statistically analyzed through STATA 12-2011. Results: In ER, we reported a 24% reduction in UPCs during the COVID-19 period (n = 909) in comparison with the pre-COVID-19 period (n = 1,194). Differently, we observed an increase of 4% in UPCs carried out in CMHS during the COVID-19 period (n = 1,214) in comparison with the previous period (n = 1,162). We observed an increase of UPCs in ER required by people who lived in psychiatric facilities or with disability pension whereas more UPCs in CMHS were required by older people or those living in other institutions compared to the previous period. In the COVID-19 period, the most frequent reasons for UPCs in ER were aggressiveness, socio-environmental maladjustment and psychiatric symptoms in organic disorders whereas in CMHS we reported an increase of UPCs for control of psychopharmacology therapy and mixed state/mania. Conclusion: In light of our findings, we conclude that the most vulnerable people required more frequent attention and care in both ER and CMHS during pandemic, which disrupted individuals’ ability to adapt and induced many stressful reactive symptoms. In order to reduce the impact of the COVID-19 pandemic on mental health, psychological support interventions for the general population should be implemented, having particular regard for more psychologically fragile people

EXPERIMENTAL AND NUMERICAL ASSESSMENT OF A LAST STAGE ST BLADE DAMPING AT LOW LOAD OPERATION

As LP steam turbines are requested to work at strong part-loads, LSB stalled and unstalled flutter may occur. Testing on a downscaled steam turbine in T10MW test plant have been carried out to measure LSB aggregated damping at low load. Also numerical analysis to predict aerodynamic damping have been performed and results have been compared to experimental data, allowing software tool validation at low load