5,397 research outputs found

    Practical Algorithms for Multicast Support in Input Queues Switches

    Get PDF
    Abstract — This paper deals with multicast flow support in N × N Input Queued switch architectures. A practical approach to support multicast traffic is presented, assuming that O(N) queues are available at each input port. The focus is on dynamic queueing policies, where, at each input port, multicast flows are assigned to one among the available queues when flows become active: flows are assigned to queues according to switch queue status and, possibly, to flow information. We discuss queueing assignments, scheduling algorithms and flow activity definition models. We explain why dynamic queueing disciplines may outperform static policies, and we show that, even in the most favorable conditions for static policies, they provide comparable performance. I

    Morphometry of the Campi Flegrei caldera (Southern Italy)

    Get PDF
    A high-resolution Digital Terrain Model (DTM) of Campi Flegrei caldera, obtained from an airborne LiDAR mission, has been analyzed in order to produce a 1:20,000-scale morphometric map of this volcanic area. The map consists of different thematic layers, which include: profile curvature, terrain ruggedness index, elevation range, as well as an up-to-date structural map and building distribution in the densely populated area. Results evidence that most of the relief is related to the occurrence of tuff-cones, tuff-ring, and the outer flanks of the caldera. Higher values of elevation characterize the upper portions of cones, while higher terrain ruggedness index values concentrate on the inner flanks of cones and in areas affected by gravity and erosional processes. The map also evidences the topographic expression of crater rims and of the major morphological scarps, which reflect ancient and uplifted shorelines and present-day cliffs

    Analytical studies on commercial artists’ colour charts from Das Deutsche Farbenbuch (1925)—identification of synthetic and natural organic colourants by Raman microscopy, surface-enhanced Raman spectroscopy and metal underlayer ATR-FTIR spectroscopy

    Get PDF
    Historical colour charts provide a rich and often well-dated reference materials source for studying the chemical composition of all kinds of commercial brands of artists' paints. This article presents the results of an extensive analytical study of more than 80 paint hues from 11 colour charts that are included in the German standard book Das Deutsche Farbenbuch by H. Trillich (1925, Part II). Our research focused on the identification of synthetic organic pigments, whose quickly increasing significance for artists' paints in the early twentieth century is impossible to evaluate by documentary source research alone. A stepwise procedure combining different non- or minimally invasive vibrational spectroscopy techniques-Normal Raman and Surface-Enhanced Raman spectroscopy as well as Metal Underlayer Attenuated Total Reflection Fourier-transform Infrared Spectroscopy-allowed the identification of 18 different organic colourants in artists' watercolours, tempera and oil colours from six German manufacturers. In addition, micro-X-Ray Fluorescence spectroscopy was applied to determine the elemental pattern of substrates, fillers, and admixed inorganic pigments. In addition to a few traditional natural organic colourants (dark and rose madder lake, cochineal lake), most of the identified compounds comprised synthetic organic pigments or synthetic dyes from various chemical classes (indigo, anthraquinone, monoazo, ss-naphthol, xanthene, triarylcarbonium, nitroso, and azine compounds). Some of these have not or only rarely been reported in artists' paints so far. Since the identified organic colourants have mainly poor to fair (only sometimes good) fastness to light according to modern standards and partially also to solvents typically used in conservation treatments, it is evident that works of art from this period should be treated keeping in mind the possible presence of such colourants, when planning both interventive treatments and preventive measures

    A randomized double-blind trial to compare the clinical efficacy of granisetron with metoclopramide, both combined with dexamethasone in the prophylaxis of chemotherapy-induced delayed emesis

    Get PDF
    Background: The prophylactic use of 5-HT3 receptor antagonists (setrons), after the first 24 h (acute phase) of exposure to emetic chemotherapy, to decrease the incidence of ‘delayed phase' emesis increases costs. We designed a study to evaluate the efficacy of a setron (granisetron) in the delayed phase, compared with metoclopramide, each combined with a corticosteroid. Patients and methods: Patients on their first course of single-day emetic chemotherapy (cisplatin, carboplatin, doxorubicin, cyclophosphamide and others) received granisetron 2 mg p.o. and dexamethasone 8 mg p.o. on day 1, followed for 5 days by dexamethasone 4 mg p.o. od combined with either metoclopramide 20 mg p.o. tds or granisetron 1 mg bd in a double-blinded double-dummy protocol. Patients evaluated the results using a diary card. Randomization was stratified by institution, sex, emetic chemotherapy naïve versus previous, alcohol consumption and platinum versus non-platinum regimen. Results: 131 evaluable patients received granisetron in the delayed phase, and 127 received metoclopramide. Control of acute emesis in both arms was similar (86% granisetron; 85% metoclopramide). The 35 patients experiencing acute emesis had poor control in the delayed phase, with only four granisetron and three metoclopramide patients having no or mild nausea and no vomiting. Conclusions: In daily practice, a combination of oral dexamethasone and oral granisetron achieves an extremely high control of acute emesis (86% protection). Our data suggest that routine prescription of setrons for delayed phase control is not advisable as it increases costs without any benefit for the majority of patients. Delayed emesis in the rare patients with acute phase emesis remains an unsolved proble
    • 

    corecore