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排序方式: 共有1385条查询结果,搜索用时 15 毫秒
31.
32.
Command governor for constrained switched systems with scheduled model transition dwell times
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In this paper, a switched control architecture for constrained control systems is presented. The strategy is based on command governor ideas that are here specialized to ‘optimally’ schedule switching events on the plant dynamics for improving control performance at the expense of low computational burdens. The significance of the method mainly lies in its capability to avoid constraints violation and loss of stability regardless of any configuration change occurrence in the plant/constraint structure. To this end, the concept of model transition dwell time is used within the proposed control framework to formally define the minimum time necessary to enable a switching event under guaranteed conditions on the overall stability and constraint fulfilment. Simulation results on a simple linear system and on a Cessna 182 aircraft model show the effectiveness of the proposed strategy. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
33.
José Maurício S. Bento Terezinha M. C. Della Lucia Rosa T. S. Frighetto 《Journal of chemical ecology》1993,19(10):2347-2351
Males of the sugarcane borer,Migdolus fryanus (Coleoptera: Cerambycidae), are attracted to females by means of a sex pheromone. Mating usually occurs during a few days from October to March under field conditions in São Paulo State, Brazil. This work reports on mating of this species as affected by daily climatic factors, during a single nuptial flight. Maximum male capture by the natural sex pheromone occurred from 1000 to 1100 AM at air and soil temperatures of 30.0°C and relative humidity of 57.0%. As these temperatures increased, females burrowed into the soil, as they are more sensitive to heat than males. Thus, it was concluded that sex pheromone-mediated mating in this cerambycid is directly affected by temperatures of air and soil. 相似文献
34.
Angelo Lucia Peter A. DiMaggio Meghan L. Bellows Leah M. Octavio 《Computers & Chemical Engineering》2005,29(11-12):2363
Normal alkanes show very complicated phase transition kinetics and macroscopic phase equilibrium behavior. This paper focuses on the phase stability and equilibrium of complicated mixtures like n-alkanes and on the enabling global optimization technologies needed to gather problem knowledge. The new ideas contained in this paper include:
- (1) novel level set methods for gathering encoded knowledge;
- (2) the differential geometry for uncovering pathways to more subtle knowledge;
- (3) all supporting non-linearly constrained optimization techniques;
- (4) all data handling needed to unravel complex solution structure.
35.
J. K. Messer Frank C. De Lucia Paul Helminger 《Journal of Infrared, Millimeter and Terahertz Waves》1983,4(4):505-539
Line positions, strengths, and absolute energies are calculated for the pure rotational spectrum of water in the region between 0 cm?1 and 877 cm?1. These calculations are done in the context of a reduced centrifugal distortion Hamiltonian, and are based on microwave measurements of this spectrum to 1 THz, and Far Infrared measurements between 32 cm?1 and 715 cm?1. 相似文献
36.
Canfora G. Cimitile A. De Carlini U. De Lucia A. 《IEEE transactions on pattern analysis and machine intelligence》1998,24(9):721-740
Constructing code analyzers may be costly and error prone if inadequate technologies and tools are used. If they are written in a conventional programming language, for instance, several thousand lines of code may be required even for relatively simple analyses. One way of facilitating the development of code analyzers is to define a very high-level domain-oriented language and implement an application generator that creates the analyzers from the specification of the analyses they are intended to perform. This paper presents a system for developing code analyzers that uses a database to store both a no-loss fine-grained intermediate representation and the results of the analyses. The system uses an algebraic representation, called F(p), as the user-visible intermediate representation. Analyzers are specified in a declarative language, called F(p)-l, which enables an analysis to be specified in the form of a traversal of an algebraic expression, with access to, and storage of, the database information the algebraic expression indices. A foreign language interface allows the analyzers to be embedded in C programs. This is useful for implementing the user interface of an analyzer, for example, or to facilitate interoperation of the generated analyzers with pre-existing tools. The paper evaluates the strengths and limitations of the proposed system, and compares it to other related approaches 相似文献
37.
We report the electro-oxidation of formaldehyde on polyaniline films modified with Pt nanoparticles (PANI-Pt films) in an aqueous sulfuric acid solution. The electrodeposition of Pt particles on the PANI matrix was found to promote a mass loss of the film, with a similar effect occurring after cycling the PANI films in the acidic medium containing formaldehyde. However, despite the electrochemical instability of PANI-Pt films, on films containing larger amounts of incorporated Pt particles, the oxidation of formaldehyde produces adsorbed CO species (COads) at a lower positive potential than on bulk Pt. Our findings also indicate that electro-oxidation of COads on the PANI-Pt film surface depends not only on the thickness of PANI film but also on the amount of Pt particles incorporated into the PANI matrix. 相似文献
38.
The Impact of Nonalcoholic Fatty Liver Disease on Renal Function in Children with Overweight/Obesity
Lucia Pacifico Enea Bonci Gian Marco Andreoli Michele Di Martino Alessia Gallozzi Ester De Luca Claudio Chiesa 《International journal of molecular sciences》2016,17(8)
The association between nonalcoholic fatty liver disease (NAFLD) and chronic kidney disease has attracted interest and attention over recent years. However, no data are available in children. We determined whether children with NAFLD show signs of renal functional alterations, as determined by estimated glomerular filtration rate (eGFR) and urinary albumin excretion. We studied 596 children with overweight/obesity, 268 with NAFLD (hepatic fat fraction ≥5% on magnetic resonance imaging) and 328 without NAFLD, and 130 healthy normal-weight controls. Decreased GFR was defined as eGFR < 90 mL/min/1.73 m2. Abnormal albuminuria was defined as urinary excretion of ≥30 mg/24 h of albumin. A greater prevalence of eGFR < 90 mL/min/1.73 m2 was observed in patients with NAFLD compared to those without liver involvement and healthy subjects (17.5% vs. 6.7% vs. 0.77%; p < 0.0001). The proportion of children with abnormal albuminuria was also higher in the NAFLD group compared to those without NAFLD, and controls (9.3% vs. 4.0% vs. 0; p < 0.0001). Multivariate logistic regression analysis revealed that NAFLD was associated with decreased eGFR and/or microalbuminuria (odds ratio, 2.54 (confidence interval, 1.16–5.57); p < 0.05) independently of anthropometric and clinical variables. Children with NAFLD are at risk for early renal dysfunction. Recognition of this abnormality in the young may help to prevent the ongoing development of the disease. 相似文献
39.
Lucia Baima Andrea Canclini Jiang Lei 《南方建筑》2016,(2):47
近几十年来,旧工业区转型的项目不断增加,范围日益扩大,内涵不断扩充,被认为是城市改造的主要途径。工业区的转型不仅是自身的需要,而且经常能提供一个现实的机会来设想与城市在功能和关系上的深远变化。因为实施的连续性和话题的扩展性,这种转型要放在社会、技术和国际化变化的语境下,考虑典型的城市改造过程中的周期性活力,作为持续演变的效果来进行分析。这种改善往往受到多方面影响,包括:该地区最初的设计、与城市中断了的互动、新的机遇以及潜在的需求。所以,转型不仅意味着现存物质空间的改变,往往还作为观念工具,提供区域层面的解决之道。 相似文献
40.
Lucia Padalino Marcella Mastromatteo Lucia Lecce Sara Spinelli Francesco Contò Matteo Alessandro Del Nobile 《International Journal of Food Science & Technology》2014,49(6):1544-1556
The goal of the study was to obtain spaghetti enriched with pea flour with sensory properties close to conventional pasta. To this aim, the study has been organised in two subsequent trials. In the first, the pea flour amount added to the spaghetti was continuously increased until the overall sensory quality reached its threshold value (pea flour concentration = 15%). In fact, the spaghetti samples supplemented with 15% pea flour (15%S‐P) showed less elasticity, unpleasant colour and higher firmness compared to the control sample (CTRL). The second step was aimed to improve the overall sensory quality of the 15%S‐P spaghetti by means of guar gum (GUAR). The sample with GUAR (15%S‐P/GUAR) showed a pleasant colour, odour and taste. Furthermore, the 15%S‐P/GUAR sample recorded a low starch digestibility value (i.e. 54) and a higher soluble fibre content with respect to the 15%S‐P sample. 相似文献