Abstract
Microgrids are the basic building cells of a smart grid. They are assumed to be established at the low voltage distribution level, where distributed energy sources, storage devices, controllable loads, and electric vehicles are integrated and need to be properly managed. The microgrid cell is a very flexible system that can be operated connected to the main power network or autonomously, in a controlled and coordinated way. When operating in islanded mode, the MG relies on local energy storage to ensure the balance between generations and loads. However, when operating isolated from the main grid, the MG is more sensitive to power quality issues such as voltage unbalance, caused by the connection of single-phase loads and sources. In order to improve the MG emergency operation conditions, the EV should be envisaged as an active and flexible entity, providing to the MG additional distributed load or storage capacity under the vehicle-to-grid (V2G) concept. This chapter reviews the MG architecture considering EV and focuses on the impact of their active participation on the MG frequency regulation in emergency conditions (namely in islanding operating mode). Voltage unbalance issues during MG autonomous operation and the need for adopting voltage balancing mechanisms in specific power electronic interfaces are also discussed. © Springer India 2014.

Abstract
The challenge of resilience for High Performance Computing applications is significant for future extreme scale systems. These systems will experience unprecedented rates of faults and errors as they will be constructed from massive numbers of components that are inherently less reliable than those available today. While the use of redundant computing can provide detection and possible correction of errors, its system-wide use in future extreme-scale HPC systems will incur considerable overheads to application performance. In this paper, we present a framework that provides application level fault detection based on redundant multithreading. In previous work, we demonstrated an adaptive approach based on a language level directive. The computation contained in the programmer directive is executed by duplicate threads. In concert with a runtime system, the redundant multithreading is enabled opportunistically to provide fault detection at more reasonable overheads to application performance. The lazy fault detection approach presented in this work seeks to further optimize the use of redundancy by prioritizing the application's primary computation over the fault detection. Our approach relaxes the requirement that the redundant threads synchronize and compare results immediately. We show that lazy error detection is feasible and yields lower time to solution over adaptive RMT for a range of scientific computational kernels. We also explore a thread-to-core assignment strategy that seeks to reduce the interference between the redundant threads. © 2014 IEEE.

Abstract

Abstract
In cloud computing environments, data storage systems often rely on optimistic replication to provide good performance and availability even in the presence of failures or network partitions. In this scenario, it is important to be able to accurately and efficiently identify updates executed concurrently. Current approaches to causality tracking in optimistic replication have problems with concurrent updates: they either (1) do not scale, as they require replicas to maintain information that grows linearly with the number of writes or unique clients; (2) lose information about causality, either by removing entries from client-id based version vectors or using server-id based version vectors, which cause false conflicts. We propose a new logical clock mechanism and a logical clock framework that together support a traditional key-value store API, while capturing causality in an accurate and scalable way, avoiding false conflicts. It maintains concise information per data replica, only linear on the number of replica servers, and allows data replicas to be compared and merged linear with the number of replica servers and versions.

Abstract
The Arrowhead project aims to address the technical and applicative issues associated with cooperative automation based on Service Oriented Architectures. The problems of developing such kind of systems are mainly due to the lack of adequate development and service documentation methodologies, which would ease the burden of reusing services on different applications. The Arrowhead project proposes a technical framework to efficiently support the development of such systems, which includes several tools for documentation of services and to support the development of SOA-based installations. The work presented in this paper describes the approach which has been developed for the first generation pilots to support the documentation of their structural services. Each service, system and system-of-systems within the Arrowhead Framework must be documented and described in such way that it can be implemented, tested and deployed in an interoperable way. This paper presents the first steps of realizing the Arrowhead vision for interoperable services, systems and systems-of-systems.

Abstract
The reduction of carbon emission is imperative towards the Green Internet. Hence, this paper proposes and validates green routing metrics focused on improving energy efficiency of multi-hop approaches in heterogeneous wireless peoplecentric environments. The validation is carried out through discrete event simulations based on real data set traces and controlled random topologies for the specific case of AODV. Results show improvements to network lifetime without penalizing other performance metrics.