Search results for "Civil engineering"
showing 10 items of 1216 documents
Using Metaheuristic and Fuzzy System for the Optimization of Material Pull in a Push-Pull Flow Logistics Network
2013
Published version of an article in the journal: Mathematical Problems in Engineering. Also available from the publisher at: http://dx.doi.org/10.1155/2013/359074 Open access Alternative material flow strategies in logistics networks have crucial influences on the overall performance of the networks. Material flows can follow push, pull, or hybrid systems. To get the advantages of both push and pull flows in networks, the decoupling-point strategy is used as coordination mean. At this point material pull has to get optimized concerning customer orders against pushed replenishment-rates. To compensate the ambiguity and uncertainty of both dynamic flows, fuzzy set theory can practically be app…
Robust ℋ∞ Dynamic Output Feedback Control Synthesis with Pole Placement Constraints for Offshore Wind Turbine Systems
2012
The problem of robust ℋ∞ dynamic output feedback control design with pole placement constraints is studied for a linear parameter-varying model of a floating wind turbine. A nonlinear model is obtained and linearized using the FAST software developed for wind turbines. The main contributions of this paper are threefold. Firstly, a family of linear models are represented based on an affine parameter-varying model structure for a wind turbine system. Secondly, the bounded parameter-varying parameters are removed using upper bounded inequalities in the control design process. Thirdly, the control problem is formulated in terms of linear matrix inequalities (LMIs). The simulation results show a…
An ANN model to correlate roughness and structural performance in asphalt pavements
2017
Abstract In this paper, using a large database from the Long Term Pavement Performance program, the authors developed an Artificial Neural Network (ANN) to estimate the structural performance of asphalt pavements from roughness data. Considering advantages of modern high-performance survey devices in the acquisition of road pavement functional parameters, it would be of practical significance if the structural state of a pavement could be estimated from its functional conditions. To differentiate various road section conditions, several significant input parameters, related to traffic, weather, and structural aspects, have been included in the analysis. The results are very interesting and …
Stochastic Vulnerability Assessment of Masonry Structures: Concepts, Modeling and Restoration Aspects
2019
A methodology aiming to predict the vulnerability of masonry structures under seismic action is presented herein. Masonry structures, among which many are cultural heritage assets, present high vulnerability under earthquake. Reliable simulations of their response to seismic stresses are exceedingly difficult because of the complexity of the structural system and the anisotropic and brittle behavior of the masonry materials. Furthermore, the majority of the parameters involved in the problem such as the masonry material mechanical characteristics and earthquake loading characteristics have a stochastic-probabilistic nature. Within this framework, a detailed analytical methodological approac…
Prediction of surface treatment effects on the tribological performance of tool steels using artificial neural networks
2019
The present paper discussed the development of a reliable and robust artificial neural network (ANN) capable of predicting the tribological performance of three highly alloyed tool steel grades. Experimental results were obtained by performing plane-contact sliding tests under non-lubrication conditions on a pin-on-disk tribometer. The specimens were tested both in untreated state with different hardening levels, and after surface treatment of nitrocarburizing. We concluded that wear maps via ANN modeling were a user-friendly approach for the presentation of wear-related information, since they easily permitted the determination of areas under steady-state wear that were appropriate for use…
Atmosphere-Space Interactions Monitor (ASIM): State of the Art
2014
Atmosphere-Space Interactions Monitor (ASIM) mission is an ESA pay load which will be installed in the Columbus module of the International Space Station (ISS). ASIM is optimized to the observation and monitoring of luminescent phenomena in the upper atmosphere, the so called Transient Luminous Event (TLEs) and Terrestrial Gamma Ray Flashes(TGFs). Both TLEs and TGFs have been discovered recently (past two decades) and opened a new field of research in high energetic phenomena in the atmosphere. We will review the capabilities of ASIM and how it will help researchers to gain deeper knowledge of TGFs, TLEs, their inter-relationship and how they are linked to severe thunderstorms and the pheno…
A new hybrid procedure for the definition of seismic vulnerability in Mediterranean cross-border urban areas
2016
Assessment of seismic vulnerability of urban areas provides fundamental information for activities of planning and management of emergencies. The main difficulty encountered when extending vulnerability evaluations to urban contexts is the definition of a framework of assessment appropriate for the specific characteristics of the site and providing reliable results with a reasonable duration of surveys and post-processing of data. The paper proposes a new procedure merging different typologies of information recognized on the territories investigated and for this reason called “hybrid.” Knowledge of historical events influencing urban evolution and analysis of recurrent building technologie…
Examining the effect of adverse weather on road transportation using weather and traffic sensors.
2018
Adverse weather related to reduced visibility caused by fog and rain can seriously affect the mobility and safety of drivers. It is meaningful to develop effective intelligent transportation system (ITS) strategies to mitigate the negative effects of these different types of adverse weather related to reduced visibility by investigating the effect of rain and fog on traffic parameters. A number of previous researches focused on analyzing the effect of adverse weather related to reduced visibility by using simulated traffic and weather data. There are few researchers that addressed the impact of adverse weather instances using real-time data. Moreover, this paper conducts comprehensive inves…
Simplified analytical model for moment–axial force domain in the presence of shear in R.C. members externally strengthened with steel cages
2015
Equations for a hand calculation of moment–axial force domain in the presence of shear for R.C. beam/column externally strengthened with steel angles and strips are developed. The analytical derivation is made assuming, for axial load and flexure, the equivalent stress-block parameters for internal forces, considering the confinement effects induced in the concrete core by external cages both in the cases of strips or angles yielding. Limit states due to bond failure, concrete crushing and yielding of steel angles and strips in flexure and in shear, including moment-to-shear interaction, are considered. The proposed model gives results in a good agreement with available experimental data an…
Cold recycling of reclaimed asphalt pavements
2018
Pavement engineers have in front of them multiple challenges linked to addressing issues related to social development and society’s expanding needs. One of the most substantial of these issues is perhaps how to effectively rehabilitate and/ or maintain the existing road network while preserving and sustaining limited natural resources. The re-usage of existing pavement materials to reconstruct/ rehabilitate our future pavements is the solution that is now more and more selected by the different road administrations around the world. However, upon closer inspection, one can find many areas and details, not negligible issues, that are simply extensions of HMA technology (i.e. mix design proc…