We devise an algorithm for finding the global optimal solution of the so-called optimal power flow problem (OPF) for a class of power networks with a tree topology, also called radial networks, for which an efficient and reliable algorithm was not previously known. The algorithm we present is called the tree reduction/expansion method, and is based on an equivalence between the input network an...

health systems research aims to understand the governance of health systems (i.e. how health systems function and perform and how their actors interact with each other). this can be achieved by applying innovative methodologies and concepts that are going to capture the complexity and dynamics of health systems when they are affected by shocks. the capacity of health systems to adapt to shocks ...

detecting anomalies is an important challenge for intrusion detection and fault diagnosis in wireless sensor networks (wsns). to address the problem of outlier detection in wireless sensor networks, in this paper we present a pca-based centralized approach and a dpca-based distributed energy-efficient approach for detecting outliers in sensed data in a wsn. the outliers in sensed data can be ca...

Synchronous electric clocks utilize power grid frequency as their timing reference. Power grid frequency deviation away from its nominal value results in synchronous electric clocks running fast or running slow (also known as the time error). In this article, statistical analysis on time error of synchronous electric clocks around the world is firstly presented using the power grid frequency me...

The continuity in the electric supply of the electric installations is becoming one of the main requirements of the electric supply network (generation, transmission, and distribution of the electric energy). The achievement of this requirement depends from one side on the structure of the electric network and on the other side on the avaibility of the reserve source provided to maintain the su...

this paper describes a study that starts with an analysis of typical energy demand profiles in a hospital setting followed by a case study of a combined cooling, heating, and power (cchp) generation system.cchp is an autonomous system that combines the generation of electrical, heating, and cooling energy.the driving units are two high-efficiency gas engines that produce electrical and heat ene...

The Smart Grid promises to reshape how electricity is generated, distributed, and used. More delocalized generation based on renewable sources will transform end-users into prosumers (producers and consumers) of energy. These will require electric and supporting ICT infrastructures to be able to openly access the energy market. In this paper, we focus on the electric infrastructure issue relate...