State-of-the-art, challenges, and future trends in security constrained optimal power flow

in Electric Power Systems Research (2011), 81(8), 1731-1741

This paper addresses the main challenges to the security constrained optimal power flow (SCOPF) computations. We first discuss the issues related to the SCOPF problem formulation such as the use of a ... [more ▼]

This paper addresses the main challenges to the security constrained optimal power flow (SCOPF) computations. We first discuss the issues related to the SCOPF problem formulation such as the use of a limited number of corrective actions in the post-contingency states and the modeling of voltage and transient stability constraints. Then we deal with the challenges to the techniques for solving the SCOPF, focusing mainly on: approaches to reduce the size of the problem by either efficiently identifying the binding contingencies and including only these contingencies in the SCOPF or by using approximate models for the post-contingency states, and the handling of discrete variables. We finally address the current trend of extending the SCOPF formulation to take into account the increasing levels of uncertainty in the operation planning. For each such topic we provide a review of the state of the art, we identify the advances that are needed, and we indicate ways to bridge the gap between the current state of the art and these needs. [less ▲]

A statement on ethics from the HEART Group.

in Anadolu Kardiyoloji Dergisi = Anatolian Journal of Cardiology (2011)

Over the past several years, the editors of leading international cardiovascular journals have met to form the HEART group and to discuss areas of growing, common interest. Recently, the HEART group has ... [more ▼]

Over the past several years, the editors of leading international cardiovascular journals have met to form the HEART group and to discuss areas of growing, common interest. Recently, the HEART group has developed a document that addresses general ethical principles in the conduct of the scientific process with which all of the editors concur. Published essentially simultaneously in all of the participating journals, including this journal, this document presents the ethical tenets accepted by all of the undersigned editors that will (continue to) guide their decisions in the editorial process. These are the general principles on which the HEART Group is based and by which we, as a group, abide; however, please note that individual journal members and their respective societies may have their own rules and regulations that supersede the guidelines of the HEART Group. [less ▲]

Static and dynamic epidemics on looped chains and looped trees

in Physical Review. E : Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics (1996), 54(4), 3499-3507

The dynamic epidemic model [N. Vandewalle and M. Ausloos, J. Phys. A 29, 309 (1996)] considers the growth of a cluster in a medium containing a fraction x of mobile "particles" that are pushed by a ... [more ▼]

The dynamic epidemic model [N. Vandewalle and M. Ausloos, J. Phys. A 29, 309 (1996)] considers the growth of a cluster in a medium containing a fraction x of mobile "particles" that are pushed by a propagation front. This model is exactly solved here on various chains and trees that contain loops following an "evolution matrix" method. The exact value for the percolation threshold x(c) and the critical exponents are calculated for static and mobile particles, respectively. Surprisingly, the mobile character of the particles affects the values of the critical exponents on chains but not on trees. Thus there is a nonuniversal behavior for dynamic epidemics even on d=1 lattices. [less ▲]

Static Detection of Thin Layers into Concrete with Ground Penetrating

in Restoration of Buildings and Monuments = Bauinstandsetzen und Baudenkmalpflege (2012), 18(3/4), 247-254

Ground Penetrating Radar (GPR) is a nondestructive technique particularly well adapted to the inspection of concrete structures and can help to determine the structure inner geometry or to detect damaged ... [more ▼]

Ground Penetrating Radar (GPR) is a nondestructive technique particularly well adapted to the inspection of concrete structures and can help to determine the structure inner geometry or to detect damaged areas. When the GPR is used on structures containing thin layers, for example the sealing layer of a concrete bridge deck or the void into a masonry wall, it is important for the radar user to know the minimum thickness required to detect and estimate the thickness of those layers. The theory of thin layer detection is based on a sine wave but, in reality, most commercial GPR systems emit a large frequency band wavelet, which undergoes attenuation into the layer. To analyze the influence of those realistic conditions on the reflection coefficient of a thin layer, we combined experimental measurements and numerical FDTD simulations. The experimental results matched the numerical predictions well, presenting a fast attenuation compared to the theoretical predictions. Nevertheless, for thicknesses inferior to λ/11, the reflection coefficient could still be considered as linearly dependent of the thickness to wavelength ratio. [less ▲]

Les statines dans la prise en charge des dyslipidémies

in Revue du Praticien (La) (2011), 61(8), 1120-1126

Statins, combined with life-style advices, have a key position in the prevention of cardiovascular diseases. By inhibiting HMG-CoA reductase enzyme, these medications reduce total and LDL cholesterol ... [more ▼]

Statins, combined with life-style advices, have a key position in the prevention of cardiovascular diseases. By inhibiting HMG-CoA reductase enzyme, these medications reduce total and LDL cholesterol levels in a dose-dependent manner. They also exert various pleiotropic effects that may contribute to the cardiovascular protection. Although some differences exist between available statins, a class effect seems predominant. Statins have proven their efficacy in numerous controlled randomized trials (recently pooled in meta-analyses), both in primary and secondary prevention, including various specific populations, among them patients with diabetes. Tolerance and safety profile is rather good even if muscular and hepatic adverse events may occur. The prescription of statins should target high-risk individuals and both therapeutic inertia and drug non-compliance should be avoided. [less ▲]

La station de Calvi et l'expérience Medalpex en Méditerranée Occidentale

in Bulletin de la Société Royale des Sciences de Liège (1983), 52(1), 51-64

La station scientifique de la Baraque Michel

in Archives Internationales de Physiologie (1924), XXIII

Les stations de pompage du bassin liégeois, un patrimoine architectural méconnu

in Nouvelles du Patrimoine (Les) (2004), 105

Statique et Dynamique des constructions maritimes et offshores

Learning material (1988)

Statistical analysis of chamber VOCs emission data

Conference (2010, January 21)