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41.
Stefano Crespi Reghizzi Dino Mandrioli 《Journal of Computer and System Sciences》2012,78(6):1837-1867
Floyd?s operator precedence grammars and languages (FG, FL) are a classical subclass of deterministic context-free (DCF) grammars and languages. We prove that several recently introduced language families motivated by the needs of model checking and of specifying XML-like languages are proper subsets of FL. The main cases considered include visibly pushdown languages (VPL) and balanced languages (BALAN), which are characterized by restricted precedence relations. FL have all the closure properties available for regular languages and generally viewed as necessary for application to model checking: reversal, prefixing and suffixing, concatenation, Kleene star, and boolean operations. All but the last results are new, and some require complex proofs, due to the necessary changes of syntax structure. Thus FL are the largest known subfamily of DCF having the same closure properties as VPL. FG, unlike VPL grammars, which are intended for abstract syntax modelling, are structurally adequate to specify real programming languages. 相似文献
42.
Liliana G. Fidalgo Mauro D. Santos Rui P. Queirós Rita S. Inácio Maria J. Mota Rita P. Lopes Mafalda S. Gonçalves Ricardo F. Neto Jorge A. Saraiva 《Food and Bioprocess Technology》2014,7(7):2028-2037
Hyperbaric storage at naturally variable room temperature (RT) conditions (18–21 °C) and above (30 °C) was evaluated as a possible new food preservation method, regardless of temperature. Preservation of watermelon juice (used as a case study of a highly perishable food) at RT and 5 °C at atmospheric pressure was compared to preservation under 100 MPa at RT. After 8 h of hyperbaric storage at 100 MPa, the initial microbial loads of the watermelon juice were reduced by 1 log unit for total aerobic mesophiles, and 1–2 log units for Enterobacteriaceae and yeasts and moulds, to levels of about 3 log units for the former and below the detection limit for the latter, and remained thereafter unchanged up to 60 h. Similar results were obtained at 30 °C at 100 MPa after 8 h. At atmospheric pressure at RT (24 h) and 30 °C (8 h), microbial levels were already above quantification limits and unacceptable for consumption. Furthermore, pressure attenuated the increase in titratable acidity verified at atmospheric pressure, but caused higher colour changes, especially a higher lightness and a lower browning degree. Post-hyperbaric storage at 5 °C revealed an extended shelf life, as an additional benefit of hyperbaric storage. These results show that hyperbaric storage is a very promising food preservation methodology. 相似文献
43.
Paola Pellegrini Franco Mascia Thomas Stützle Mauro Birattari 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2014,18(11):2177-2190
In this paper, we assess the sensitivity of reactive tabu search to its meta-parameters. Based on a thorough experimental analysis of reactive tabu search applications to the quadratic assignment and the maximum clique problem, we show that its performance is relatively insensitive to its meta-parameters. This is particularly evident when compared to the sensitivity of tabu search to its parameters: tabu search is rather penalized if used with sub-optimal parameter settings. Reactive tabu search does not strongly pay its high parameter robustness in terms of performance, although it does not improve the peak performance of tabu search. 相似文献
44.
Traffic geometry is a factor that contributes to cognitive complexity in air traffic control. In conflict‐detection tasks, geometry can affect the attentional effort necessary to correctly perceive and interpret the situation; online measures of situational workload are therefore highly desirable. In this study, we explored whether saccadic movements vary with changes in geometry. We created simple scenarios with two aircraft and simulated a conflict detection task. Independent variables were the conflict angle and the distance to convergence point. We hypothesized lower saccadic peak velocity (and longer duration) for increasing complexity, that is, for increasing conflict angles and for different distances to convergence point. Response times varied accordingly with task complexity. Concerning saccades, there was a decrease of peak velocity (and a related increase of duration) for increased geometry complexity for large saccades (>15°). The data therefore suggest that geometry is able to influence “reaching” saccades and not “fixation” saccades. © 2011 Wiley Periodicals, Inc. 相似文献
45.
46.
La Russa Mauro F. Ruffolo Silvestro A. de Buergo Mónica Álvarez Ricca Michela Belfiore Cristina M. Pezzino Antonino Crisci Gino M. 《Bulletin of Engineering Geology and the Environment》2017,76(1):115-124
Bulletin of Engineering Geology and the Environment - Salt crystallization is a strong weathering agent in porous building materials. The crystallization pressure exerted by salt crystals, growing... 相似文献
47.
This paper presents a survey on Nonlinear Analog-to-Digital converters (ADC). This class of converters is extremely relevant in applications where there is a need for non-uniform quantization characteristic, for example, some specific applications in the areas of light detection, hearing aid, nuclear physics, image acquisition, communication systems, etc. This survey outlines the state-of-the-art Nonlinear ADC topologies, such as, floating point, logarithmic, piecewise linear and oversampled nonlinear converters, and discusses their performance and advantages in terms of their applications. 相似文献
48.
Mauro Dell'Orco Mario Mellano 《Computer-Aided Civil and Infrastructure Engineering》2013,28(8):635-647
Users of road facilities generally express a judgment on road quality based on their psychophysical conditions, in relation to the environment they refer to. This judgment is made considering many aspects, for example, the presence of traffic lights, the frequency of interchanges, of lay‐bys and gas stations, route conformation, environmental conditions, quality of road signs, etc. In this article, we propose a new index called Global Satisfaction Index, which uses vehicular traffic quality and quality of road pavement, to summarize these aspects, and to express the users’ global judgment about the ride comfort on rural roads. Since in this kind of judgment a subjective perception process is involved, we have used fuzzy theory to handle uncertainty embedded in the process. The attributes of the aspects considered have been expressed through fuzzy numbers, and the global judgment has been obtained through a fuzzy inference system. In this way the proposed index overcomes the limits of other existing indices, since it incorporates uncertainties and/or imprecision inherent in the drivers’ perception of the ride comfort. Moreover, it can be used for evaluation and comparison of different types of road sections. Finally, a numerical example is presented to assist in understanding the practical aspects of the proposed index. 相似文献
49.
Mauro Marangoni Lukas Arnout Lieven Machiels Lieven Pandelaers Enrico Bernardo Paolo Colombo Yiannis Pontikes 《Journal of the American Ceramic Society》2016,99(6):1985-1991
The present paper deals with the synthesis of porous, sintered glass‐ceramics obtained at temperatures below 1150°C, originating from inorganic polymers based on fayalite slag. Firing led to the evaporation of water, dehydroxylation, and oxidation of Fe2+ above 345°C. For heating >700°C, the Si–O stretching band shifted from the 1160 and 750 cm?1 to the 1255 and 830 cm?1 region, due to a structural reorganization of the amorphous phase, whereas Fe–O bands appeared at 550 cm?1. The final microstructure consisted predominantly of an amorphous phase, hematite, and franklinite. The open porosity and compressive strength decreased and increased, respectively, as the firing temperature increased. The final values suggest properties comparable to that of structural lightweight concrete, still, the materials synthesized herein, are lighter, and made primarily from secondary resources. 相似文献
50.
Gaona-Martínez Mauro J. Guajardo-López Laura N. Pérez-Patiño Juan A. Ramírez-Ramírez Javier H. Pérez-González Francisco A. Colás Rafael Garza-Montes-de-Oca Nelson F. 《Oxidation of Metals》2019,91(5-6):641-656
Oxidation of Metals - The oxidation characteristics of a roll-grade high-speed steel with different tempering heat treatments were studied under thermal cycling conditions at 650 °C... 相似文献