Search results for "Systems engineering"
showing 10 items of 1230 documents
H∞ sliding mode control for uncertain neutral-type stochastic systems with Markovian jumping parameters
2015
This paper is devoted to the investigation of H ∞ sliding mode control (SMC) for uncertain neutral stochastic systems with Markovian jumping parameters and time-varying delays. A sliding surface functional is firstly constructed. Then, the sliding mode control law is designed to guarantee the reachability of the sliding surface in a finite-time interval. The sufficient conditions for asymptotically stochastic stability of sliding mode dynamics with a given disturbance attenuation level are presented in terms of linear matrix inequalities (LMIs). Finally, an example is provided to illustrate the efficiency of the proposed method.
First-Principles Calculations of SrZrO3 (001) Surfaces
2011
The results of calculations of surface relaxations, rumplings, and charge distribution for the SrZrO3 (001) surface using ab initio code CRYSTAL and a hybrid description of exchange and correlation are presented. Both SrO and ZrO2 terminations of the SrZrO3 (001) surface are considered. On the (001) surfaces all upper and third layer atoms relax inward, while outward relaxations of all atoms in the second layer are found with the sole exception of SrO-terminated SrZrO3 (001) surface second layer O atom. Calculated surface rumpling for the SrO-terminated SrZrO3 (001) surface 6.77% of the lattice constant is by a factor of ten larger than the surface rumpling for the ZrO2-terminated SrZrO3 (0…
AB INITIO CALCULATIONS OF SrTiO3, BaTiO3, PbTiO3, CaTiO3 AND BaZrO3 (001) AND (011) SURFACES
2009
I present results of calculations of surface relaxations and rumplings for the (001) and (011) surfaces of BaZrO3 and ATiO3 perovskites (A = Sr, Ba, Pb and Ca) using a hybrid B3PW description of exchange and correlation. The (001) surface energies of AO, TiO2 and ZrO2 terminations are found to be comparable with each other for all five materials. The surface energies for BaZrO3, SrTiO3, BaTiO3, PbTiO3 and CaTiO3 (011) surfaces for all terminations are considerably larger than for (001) surfaces. We predict a considerable increase in the Ti-O (Zr-O) chemical bond covalency near the (011) surface as compared both to the bulk and to the (001) surface.
Comparison of leaf surface roughness analysis methods by sensitivity to noise analysis
2015
International audience; Surface roughness is of great interest in agricultural spraying because it is used to characterise leaf surface wettability to predict the behaviour of droplets on a leaf surface. In recent years, the use of texture analysis to estimate surface roughness has emerged. In this paper we propose to estimate leaf surface roughness by using an optimisation of the Generalized Fourier Descriptors method. This approach is then compared with two other standard methods in the literature, one based on grey level intensity variation and the other on wavelet decomposition. Since roughness has many definitions and each method is calculated differently, we propose a new approach to …
Special Issue on “Recent Developments on Modeling and Control of Hybrid Electric Vehicles”
2016
Environmental pollution and energy shortages are not only the two major problems currently in the sustainable development of the automotive industry, but also the two major bottlenecks in the global automotive industry. Facing the enormous requirement of energy-saving and environment protection, the development of new energy vehicles have become an important measure to solve this problem. Recently, hybrid electric vehicles (HEVs) or electric vehicles (EVs) have become a hot topic from both theoretical and practical perspectives. Among various types of electric vehicles, hybrid electric vehicles (HEVs) — or as they are commonly dubbed “hybrid vehicles” — offer the distinct advantages of ener…
Smart Sustainable Development Approach and its Implementation in Engineering Organizations
2014
This paper explores the concept of sustainability in engineering systems and proposes a smart conceptual framework for engineering organization development. Sustainability is a critically complex goal for enterprise activity and development. Sustainability in the engineering area requires a comprehensive and continue approach because, a) engineering activities are ubiquitous in society, b) of the high importance of engineering applications in the development of the companies and of the world, and c) technological support becomes imminent in a dynamic economic environment and sustained in large part by technological advances. This paper aims to provide to the engineering environment a smart …
Management of intelligent transport systems applied to sustainable development of motor vehicle transports
2021
The scientific paper presents a concrete research carried out by the authors in order to implement technical concepts, so that those interested in this field can learn about a certain way of exposing the problems with regard to the sustainable development of road transport. The use of computer means in the field of motor vehicle transport have taken on a special magnitude in recent times, and the Intelligent Transport Systems (ITS), also known as telematics systems used in the field of transport, comprise a wide range of tools and services deriving from ITS technologies, by using communications and information technology. Below we present a technical and managerial study with engineering nu…
Order allocation in a multiple suppliers-manufacturers environment within a dynamic cluster
2015
This study faces the problem of how to evaluate order allocation strategies in a multiple suppliers-manufacturers environment within a dynamic industry cluster that is an environment in which suppliers adopt a policy based on their performance to select the clusters in which to operate. Therefore, the allocation strategy performed by the manufacturers is crucial to keep a long-term supply chain partnership with a specific industry cluster. We use simulation to evaluate order allocation strategies under different market conditions. We show how an allocation strategy that takes into account the whole supply chain’s perspective leads to a sustainable development of the clusters of suppliers.
Sustainability in Road Design: A Methodological Proposal for the Drafting of Guideline.
2012
Abstract This paper, starting from the U.S. experience (USGBC LEED) in the building field, through GBC ITALIA, underlines the need of a specific methodological approach in our country for a roads sustainable design. Therefore, we propose criteria for the methodological approach of a handbook of sustainability. In this guideline required and voluntary project requirements are identified; for each of these objectives, benefits, standards of reference and its methods of implementation are suggested. The above guideline, using detailed development tools (VA, LCA), could provide guidance to the road-designer in the evaluation and selection of strategies to drawing-up project performance standard…
FLEX: ESA's Earth Explorer 8 candidate mission
2012
In this paper we present the scientific objectives of the FLEX mission and the underlying rationale. It sketches the basic ideas of the new measurement concept, which is making use of the tandem configuration of FLEX with GMES/Sentinel-3, and outlines the most important instrument and system requirements. We will describe the envisaged instrument configuration that is in line with the measurement objectives, and which is supported by the latest results of the scientific investigations.