1,104 research outputs found
Adaptive Quantisation in HEVC for Contouring Artefacts Removal in UHD Content
Contouring artefacts affect the visual experience of some particular types of compressed Ultra High Definition (UHD) sequences characterised by smoothly textured areas and gradual transitions in the value of the pixels. This paper proposes a technique to adjust the quantisation process at the encoder so that contouring artefacts are avoided. The devised method does not require any change at the decoder side and introduces a negligible coding rate increment (up to 3.4% for the same objective quality). This result compares favourably with the average 11.2% bit-rate penalty introduced by a method where the quantisation step is reduced in contour-prone areas
A multiscale feature extraction approach for 3D range images
This paper presents a multiscale feature extraction technique for 3D range images. Optimized and improved 3D Gaussian filtering and saliency map computation have been conceived jointly to the exploitation of connectivity relationships naturally induced by the 2D acquisition grid. The proposed algorithmic and implementation solutions guarantee good repeatability of detected features on different views and demonstrated superior computational performance compared to other known approaches
The role of storage in emerging country scenarios
AbstractDespite the electrical energy scenarios are quite different between industrialized countries and emerging and developing ones, for both contexts, energy storage systems could play a key role in the next future. Specifically, in emerging and developing countries, energy storage systems may allow a cost-effective exploitation of renewable sources in order to cope with energy security for centralized energy systems, but mainly to become a building block of rural electrification by off-grid power systems. In this paper a short overview of energy storage systems within the emerging and developing countries scenarios is reported. Specifically the paper provides a description of the typical configuration for batteries within off-grid systems and an overview of the typical economic models for batteries applications and the regulatory frameworks when off-grid applications are introduced. Finally the description of an experimental project in rural area of Tanzania points out the peculiar characteristics of batteries application in off-grid applications
Sexual Dysfunction in Men Receiving Methadone Maintenance Treatment: Clinical History and Psychobiological Correlates
A variety of studies evidenced a relationship between drug use disorders and sexual dysfunction. In particular, heroin and opioid agonist medications to treat heroin dependence have been found to be associated with erectile dysfunction and reduced libido. Controversial findings also indicate the possibility of factors other than the pharmacological effects of opioid drugs concurring to sexual dysfunction. With the present study, we investigated the link between sexual dysfunction and long-term exposure to opioid receptor stimulation (heroin dependence, methadone maintenance treatment, methadone dosage), the potentially related hormonal changes reflecting hypothalamus-pituitarygonadal axis function and prolactin (PRL) pituitary release, the role of adverse childhood experiences in the clinical history and the concomitant symptoms of comorbid mental health disorders in contributing to sexual problems. Forty male patients participating in a long-term methadone treatment program were included in the present study and compared with 40 healthy control subjects who never used drugs nor abused alcohol. All patients and controls were submitted to the Arizona Sexual Experiences Scale (ASEX), Child Experiences of Care and Abuse-Questionnaire (CECA-Q) and the Symptom Check List-90 Scale. A blood sample for testosterone and PRL assays was collected. Methadone dosages were recorded among heroin-dependent patients on maintenance treatment. Methadone patients scored significantly higher than controls on the 5-item rating ASEX scale, on CECA-Q and on Symptoms Check List 90 (SCL 90) scale. Testosterone plasma levels were significantly lower and PRL levels significantly higher in methadone patients with respect to the healthy control group. ASEX scores reflecting sexual dysfunction were directly and significantly correlated with CECA-Q neglect scores and SCL 90 psychiatric symptoms total score. The linear regression model, when applied only to addicted patients, showed that methadone dosages were not significantly correlated with sexual dysfunction scores except for 'erectile dysfunction', for which an inverse association was evidenced. Testosterone values showed a significant inverse correlation with ASEX sexual dysfunction scores, CECA-Q neglect scores and psychiatric symptom at SCL 90 among methadone patients. PRL levels were directly and significantly correlated with sexual dysfunction scores, psychiatric symptoms at SCL 90 and CECA-Q neglect scores. Both testosterone and PRL did not correlate with methadone dosages. The present findings appear to support the view of childhood adversities and comorbid psychiatric symptoms contributing to sexual dysfunction and related hormonal changes among methadone patients, challenging the assumption that attributes sexual problems entirely to the direct pharmacological effects of opioid agonist medications
Structure and morphology of shape-controlled Pd nanocrystals
Pd nanocrystals were produced with uniform truncated-cube shape and a narrow size distribution, yielding controlled surface area fractions from low Miller index ({100}, {110}, {111}) crystalline facets. Details on the structure and morphology of the nanocrystals were obtained by combining X-ray powder diffraction line profile analysis, high-resolution transmission electron microscopy and surface electrochemistry based on Cu underpotential deposition.ML acknowledges support from the Italian government (Ministero dell’Istruzione, dell’Università e della Ricerca) through the project FIRB Futuro in Ricerca RBFR10CWDA. JMF acknowledges financial support from the MINECO (Spain) project CTQ2013-44083-P and Generalitat Valenciana project PROMETEOII/2014/013
Clip-Air, a flexible air transportation system
We introduce a concept of flexible air transportation system called Clip-Air. It is a modular innovative aircraft. The flexibility provided by Clip-Air is due to the decoupling of load and carrying units. In this paper, we introduce the concept, and analyze the impacts from the airlines perspective. An integrated schedule design and fleet assignment model is developed for both standard airline fleets and Clip-Air. The model considers spill and recapture effects to represent the demand in case of capacity shortage. Recapture ratios between available itineraries in each market segment are appropriately calculated through an itinerary choice model. The comparative analysis is carried out under different scenarios which are selected with the purpose of understanding the effects of the network structure, fleet size, fleet configuration and the estimated cost figures for the Clip-Air system. It is observed that Clip-Air is able to carry on the average 5-10 % more passengers by using 20-30 % less overall capacity. Moreover, Clip-Air is found to deal better with insufficient transportation capacity. Furthermore, the scheduling decisions are robust to the estimated cost figures of Clip-Air. For the analyzed range of costs Clip-Air is always carrying more passengers with less allocated capacity compared to standard fleet
Direct oral Xa inhibitors versus warfarin in patients with cancer and atrial fibrillation: a meta-analysis
Patients with cancer are at higher risk of atrial fibrillation, thromboembolic complications and bleeding events compared with the general population. The aim of the present meta-analysis was to compare the efficacy and safety of direct oral Xa inhibitor anticoagulants versus warfarin in patients with cancer and atrial fibrillation
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