Search results for "ail"

Time-varying Sampled-data Observer with Asynchronous Measurements

2019

International audience; In this paper a time-varying observer for a linear continuous-time plant with asynchronous sampled measurements is proposed. The observer is contextualized in the hybrid systems framework providing an elegant setting for the proposed solution. In particular some theoretical tools are provided, in terms of LMIs, certifying asymptotic stability of a certain compact set where the estimation error is zero. We consider sampled asynchronous measurements that occur at arbitrary times in a certain window with an upper and lower bound. The design procedure, that we propose for the selection of the time-varying gain, is based on a constructive algorithm that is guaranteed to f…

Dissipativity-Based Small-Gain Theorems for Stochastic Network Systems

2016

In this paper, some small-gain theorems are proposed for stochastic network systems which describe large-scale systems with interconnections, uncertainties and random disturbances. By the aid of conditional dissipativity and showing times of stochastic interval, small-gain conditions proposed for the deterministic case are extended to the stochastic case. When some design parameters are tunable in practice, we invaginate a simpler method to verify small-gain condition by selecting one subsystem as a monitor. Compared with the existing results, the existence-and-uniqueness of solution and ultimate uniform boundedness of input are removed from requirements of input-to-state stability and smal…

Procedure for a Temperature-Traffic Model on Rubberized Asphalt Layers for Roads and Railways

2017

The impact of temperature on the mechanical properties and thermal susceptibility of the railway bituminous sub-ballast layer, has served as motivation to develop the advanced measurement of thermal cycles in this layer and, an evaluation of the average seasonal temperatures interpolated by sinusoidal functions, of which characteristic parameters are determined. According to weather situation, Barber’s temperature model was used to prove the effectiveness for the railway superstructure. It is included the assessment of improved modified asphalt mixes performed with coarse rubber from scrap tires, having 1.5 to 3 percent of crumb rubber (particle size 0.2-4 mm) by weight of the total mix, as…

The ELECTRE I method to support the FMECA

2018

Abstract In traditional Failure Modes, Effects and Criticality Analysis (FMECA), risk priorities of failure modes are determined through the Risk Priority Number (RPN), which is a function of the three risk parameters Occurrence (O), Severity (S), and Detection (D). In the present paper, an alternative approach to RPN is proposed for the criticality assessment of system failure modes. Particularly, the Multi-Criteria Decision Making (MCDM) method ELECTRE I is proposed to select the most critical failure mode in the set of the failure modes charactering a complex system. The method has been applied to a case study previously proposed by Zammori and Gabrielli (2012).

A Mechanical Approach for Evaluating the Distribution of Confinement Pressure in FRP-Wrapped Rectangular Columns

2019

In recent decades, fiber reinforced polymer (FRP) wrapping has become a common technique to retrofit reinforced concrete (RC) columns. Numerous research works have sought to verify analytically and experimentally its effectiveness in terms of enhancement of axial load bearing capacity and ductility. These studies highlighted that in the case of sharp-cornered sections, the maximum allowable confinement pressure is limited by premature failure at corners and, consequently, stress in the FRP, as well as the distribution of the confinement pressure, is not uniform. The prediction of this phenomenon is not straightforward, and existing theoretical studies propose complex numerical simulations, …

The bearing capacity of footings on sand with a weak layer

2017

Minor details of the ground, such as thin weak layers, shear bands and slickensided surfaces, can substantially affect the behaviour of soil–footing and other geotechnical systems, despite their seeming insignificance. In this paper, the influence of the presence of a thin horizontal weak layer on the ultimate bearing capacity of a strip footing on dense sand is investigated by single-gravity tests on small-scale physical models of the soil–footing system. The test results show that the weak layer strongly influences both the failure mechanism and the ultimate bearing capacity if its depth is lower than about four times the footing width. It is found that the presence of a thin weak layer …

Sustainable growth and environmental catastrophes

2017

Abstract In the standard AK growth model we introduce the threat of an ecological catastrophe and study the consequences for the economic variables in the long-run. We extend the basic framework by considering two environmental externalities: the first one is local and gives account of the marginal damage from emissions flow; the second one is aggregate, or global, and relates to the extreme damage which may happen if the accumulated stock of pollutants is on the threshold of a worldwide catastrophe. In this context dominated by market failures, we focus on the socially optimal solution and the search of conditions for sustainability. We identify the efficient balanced growth path, which ma…

Iron deficiency and risk of early readmission following a hospitalization for acute heart failure

2016

Biowaiver Monograph for Immediate-Release Solid Oral Dosage Forms: Amoxicillin Trihydrate

2018

Literature and experimental data relevant to waiver of in vivo bioequivalence (BE) testing for the approval of immediate-release solid oral dosage forms containing amoxicillin trihydrate are reviewed. Solubility and permeability characteristics according to the Biopharmaceutics Classification System (BCS), therapeutic uses, therapeutic index, excipient interactions, as well as dissolution and BE and bioavailability studies were taken into consideration. Solubility and permeability studies indicate that amoxicillin doses up to 875 mg belong to BCS class I, whereas 1000 mg belongs to BCS class II and doses of more than 1000 mg belong to BCS class IV. Considering all aspects, the biowaiver pro…

Mineral analysis of human diets by spectrometry methods

2016

Abstract Mineral element determination in human diets is very important for human health, due to the presence in foods of essential and toxic elements or their incorporation in the manipulation and cooking food process. Different instrumental techniques have been used to determine mineral elements in human diets, but atomic spectroscopy and mass spectrometry based ones are the most commonly employed. Sampling procedures for diet analysis are the main critically step for mineral element determination, being employed different standardised protocols. This review summarised critically the state-of-the-art of mineral analysis in human diets, considering sampling, sample preparation and determin…