Search results for " Active"
showing 10 items of 533 documents
Bourgogne, l'entrée des jeunes dans la vie active
1983
Dans quelles conditions les jeunes, sorties à différents niveaux du système éducatif, vont-ils pouvoir s'insérer dans le monde du travail, en Bourgogne ? Dans quels secteurs d'activité se retrouvent ces débutants après leur scolarité ? Par quels emplois ? Dans le système scolaire, il existe une différenciation marquée entre les filières menant aux différents baccalauréats, entre l'enseignement général et l'enseignement technique, entre les spécialités industrielles de CAP ou tertiaires de BEP, entre les classes d'enseignement général et les classes pré-professionnelles ... Cette hiérarchisation omniprésente, liée à l'orientation des élèves, influe sur les sorties des jeunes à différents niv…
Marchés du travail et disparités régionales en Pologne
2001
This article evaluates empirically the effect o f market introduction on the level o f regional inequalities and on the polarisation o f economic activities in Poland. We note an increase o f the disparities between regions over the relevant period. The re-polarisation process cannot been explained by a spatial re-allocation of labour force but rather results o f the differentiation of sectoral restructuring between regions the regional diversity o f sectoral adaptation. The search for agglomeration economies explains the spatial concentration o f services and o f added value in the regions where the biggest cities are located. A cumulative process o f agglomeration is observed. Therefore, …
Hypothalamic glucose sensing : mitochondrial dynamic involument in reactive oxygen species signaling
2011
Energetic homeostasis results in the balance between energy intake and expenditure. The hypothalamus plays an important role in the regulation of both energetic metabolism and food intake in sensing hormonal and metabolic signals. For instance, changes in hypothalamic glucose level modulate food intake and insulin secretion. We have previously found that 1) increased hypothalamic glucose level triggers production of mitochondrial reactive oxygen species (mROS) from the electron transport chain; 2) hypothalamic mROS production is involved in glucose homeostasis and food intake control. The molecular mechanisms involved in glucose-induced hypothalamic mROS production are still unknown. Mitoch…
Online optimization of a multi-conversion-level DC home microgrid for system efficiency enhancement
2017
In this paper, an on-line management system for the optimal efficiency operation of a multi-bus DC home distribution system is proposed. The operation of the system is discussed with reference to a distribution system with two conversion stages and three voltage levels. In each of the conversion stages, three paralleled DC/DC converters are implemented. A Genetic Algorithm performs the on-line optimization of the DC network’s global efficiency, generating the optimal current sharing ratios of the concurrent power converters. The overall DC/DC conversion system including the optimization section is modelled using MATLAB/Simulink. Thanks to the implemented online algorithm, considering …
Secondary substation power line communications for medium voltage smart grids
2012
In this paper a performance analysis is carried out, in order to evaluate the possibility to employ power line communication (PLC) between secondary substations of a medium voltage (MV) distribution networks in a smart grid. The study is focused on the analysis of PLC technologies and the evaluation of the influence quantities on the communication performance in the most common case of by-pass connection at MV bus-bars of secondary substations. Different quantities have been analyzed as modulation techniques, requested bandwidth and bitrate, coupling device and system attenuation versus frequency in order to find the best solution for a reliable communication system. A complete model of a r…
Modelling nanoscale fluid dynamics and transport in physiological flows
1996
The concept of nanotechnology is discussed, and its connection with biomedical engineering is elucidated. For the specific field of nanoscale flow and transport problems of physiological relevance, some typical examples are presented, and their interaction is discussed for some classic biomechanical problems like the flow in arteries with blood-wall coupling. Then, existing computational models are presented and classified according to the length scale of interest, with emphasis on particle-fluid problems. Final remarks address the essential unity of biomedical and engineering behaviour and the possible relevance to small-scale industrial research.
Performances Comparison for a Rotating Shaft Suspended by 4-Axis Radial Active Magnetic Bearings via 𝜇 -Synthesis, Loop-Shaping Design, and Sub ( 𝐻…
2011
The control systems applied on active magnetic bearing are several. A perfect levitation is characterized by maintaining the operating point condition that is characterized by the center of stator coincident with the geometric center of shaft. The first controller implemented for this purpose is PID controller that is characterized by an algorithm that leads the amplifier to produce control current until the operating point condition is not reached, this is obtained by an integration operator. The effect of an integrator is essential but not necessary for a centered levitation for example in the robust control characterized by a dynamic model depended on plant of system so that it depends o…
On the use of narrow band power line as communication technology for medium and low voltage smart grids
2012
The aim of this work is to perform a feasibility study on the power line communication for the development of a new generation of interface devices (IDs) for smart grid applications. More in detail, this paper deals with one of the most important issues on this topic which is the communication system. Among the existing communication technologies, the study is focused on power line communications (PLCs). After a analysis of the state of the art in the field, the main aspects are analyzed, concerning the open issues on the use of PLCs, especially for medium voltage (MV) and low voltage (LV) systems. In this work the use of PLC in MV-LV networks is investigated, by means of simulations and ex…
Hybrid passive and communications-based methods for islanding detection in medium and low voltage smart grids
2013
Islanding condition takes place when a distributed generator (DG) continues to power a part of the grid even if power from electric utility is no longer present. Adverse effects of islanding are power quality deterioration, grid-protection interference, equipment damage, and personnel safety hazards. For these reasons, DG systems must detect an islanding condition and immediately disconnect from the grid (anti-islanding protection). This paper proposes an hybrid solution, for both low voltage (LV) and medium voltage (MV) applications, which makes use of passive and communication-based methods for islanding detection. Among the existing communication technologies, the study is focused on pow…